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Holtzauge
02-25-2005, 12:39 PM
I must say that I'm very glad to read the reply by crazyivan1970 that the issue about the 151/20 belting/effectiveness will be corrected if we (the community) can come up with solid IRL data to convince the development team to correct this! Great news!

I'm goin to try if this works then:

The accuracy of the Mk 108 cannon needs to be corrected in the sim. In the sim the plane shakes like it's goin to fall to pieces and the Mk 108 throws the shells all over the place. This is not historically correct.

I have always been suspicious of this trait but since I had no data before I know better than to bring it up. However, I always thought that a cannon when connected to a solid mass like the engine by a hefty looking flange should keep the gun pretty still while firing. Since I've been a bit annoyed with the Mk108 ingame accuracy you can imagine my pleasure when I found the documents listed below!

References:

1) D. (Luft) T.2109 G-6/U4 teil 8A heft 1 Ausgabe April 1944. (This is part 8A of the Me 109 G6 a/c manual which covers the gun installation of the U4 variant which was equipped with a Mk 108 instead of a 20 mm in the nose)

2) Ta152 H-0 und H-1 Vorlaufiges Flugzeug-Handbuch, Schusswaffenanlage, Dezember 1944

In both these sources there are parts about how to calibrate the guns.

In ref 2, Schusswaffenanlage, page 40, section 13, the following spread is allowed for the gun installation:

At 100m Mk108: All shells should hit within an area of height 35 cm and width 30 cm.

At 100m 151/20 installation: All shells should hit within an area of height 70 cm and width 60 cm.

In ref 1, for the Mg131 installation in the G6/U4 the accuarcy requirement is height 100 cm and width 100 cm

From this we can deduce that the aircraft manuals require a higher level of accuracy for the Mk108 installation than for the 151/20 or Mg131 installations.

I have data for MG17 and 151/20 installation in the 190 A series too, but they are in the same ballbark as were the Mg131 and 151/20 in the Me 109 and Ta152.

And incidentally, while this is not mentioned in the German sources above, a rule of thumb is that about 75% of the shells fired fall within a quarter of the area which encompasses 100%, that is 75% of the shell of the Mk108 should hit within an area of 17.5 and 15 cm at 100 m.

So how does this compare with the accuracy we see in the game? I think we all know the answer to that one........

I will be out of the office for a week starting tomorrow but I look forward to coming back to a fixed Mk108. All it takes is some solid IRL data right?

Von_Zero
02-25-2005, 02:46 PM
too bad ppl like Hayate Hater and others will pop up transforming this thread in a mess http://forums.ubi.com/images/smilies/16x16_smiley-sad.gif
anyway, the area withing the bullet should hit, was tested after the instalation right? then i suppose they measured it with the plane on the ground. So, here is my question: how much of the recoil of the gun /shake of the plane, would be influenced by the fact the plane was on a solid base?( on ground)

Hunde_3.JG51
02-25-2005, 03:09 PM
I have to disagree, mainly because of my conversation with Gottfried Dulias, a real 109G-14A/S pilot with whom I spoke. He used the 30mm (he called it 3cm) MK-108 to score his 5 victories, and this is what he told me;

He stated that the 3cm cannon was incredibly powerful, one time he hit a Spitifre that he bounced (with a single round) in the rear fuesalage and it tore the back of the plane off completely and it "flipped over itself through the air." He felt that it was a good air to air weapon, and not just useable against bombers. He did however state that you needed to be at close range when shooting, and he became very animated when acting as if he was shooting the MK-108. He stated that the entire plane shook and you were jolted around in the cockpit when firing, so that anything but a short burst was ineffective.

Anyway, this was his experience and it was good enough for me to feel confident that the MK-108 was a very good weapon, it just had to be fired at close range because heavy recoil affected accuracy. Also, the accuracy of the 108 in-game is actually better than it was before, sometimes I feel that it may be too good. Still, I like using the "noob" MK-108 becuase IRL it was a very good weapon and the lack of effectiveness of the 151/20 removes any feelings of guilt (that would be unjustified anyway).

VFA195-MaxPower
02-25-2005, 03:27 PM
The mk108 is very accurate and powerful. I don't think it needs any changing at all.

The accuracy of the weapon has nothing to do with the behaviour of the aircraft. The mk108 fires like a 'laser torpedo' as someone once said in the forums.

I fly LW planes almost exclusively (except for the odd p51), and I don't think there is anything to complain about in the mk108.

crazyivan1970
02-25-2005, 03:31 PM
At least lets not bring MK108 into conversation. That thing is a monster...any way you look at it.

Did i tell you she`s my favorite http://forums.ubi.com/groupee_common/emoticons/icon_biggrin.gif

jurinko
02-25-2005, 03:40 PM
do not mix the dispersion of a gun, when tightly mounted for test shooting (then the shots may be really very concentrated) and the same on the plane in the air, when recoil shakes the plane and hits are scattered all around. If you shoot with pistol with bigger dispersion you willl get better results than hand firing the heavy machinegun with lower dispersion, as heavy recoil will spoil your aim.
MK108 is modelled quite good now, even i took it very rarely and only into late Fw 190A series.

p1ngu666
02-25-2005, 04:27 PM
its pretty acurate, p1ss poor ballistics, but so did real thing, doesnt shake the plane that much (flown a il2 lately?)

make a test runway, put a buliding by the side or whatever, use chocks and fire at it.
probably pretty lazer.

iirec oleg said he made mk108 5% stronger than it should be, and ns37 or similer 5% weaker cos of luftwhines.

if u dont think mk108 is modeled more or less fine or better than it should be, your probably off your rocker

Blutarski2004
02-25-2005, 04:54 PM
Interesting post Holtzauge (wooden eye?)

Your data translate to the following -
Mk108: 100 pct dispersion zone = 3 mils
151/20: 100 pct dispersion zone = 6 mils

Compared to USAF data -
Ms 50cal: 100 pct dispersion zone = 8 mils

The exterior ballistics rule of thumb is that, all other things being equal, accuracy approximately varies inversely with caliber. Your data fit perfectly with this rule.

Also, I'm pretty confident that your data must reflect performance of the guns in an a/c mounting, since IMO much better accuracy should be expected from such guns.

As regards recoil forces, muzzle energy of an individual round is:
Mk108 - 41250 joules
151/20 - approx 30000 joules

For comparison
Mk103 - 119000 joules

It would seem that the Mk103, with its lower RoF, would give about the same muzzle energy value per unit of firing time as the 151/20, which had a slightly higher RoF. Hmmmm. Is it possible that the Finnish pilot in Hunde's story actually was shooting a Mk 103?????

BTW, if you have not visited -

http://prodocs.netfirms.com/

recently, do so. Ring has posted more cool stuff.

carguy_
02-25-2005, 05:31 PM
Naaah I don`t think there`s any need to spoil the MK108 once again.
It has HUGE ineffectiveness problems with bombers.Test it on DB3 you`ll see what I`m saying.

About ballistics I don`t have complaints but seeing a fighter hit with 3 of those monsters smoking I nod me head.IMO the MK108 was best in IL2 v1.20.

Compare it with MK103.If one round makes energy almost 4 times the MK103 round then it should simply tear everything it hits.Again,try this on DB3http://forums.ubi.com/groupee_common/emoticons/icon_wink.gif

Willey
02-25-2005, 06:48 PM
This little table shows some deviation values for the MK 101, 103 and 108.

http://home.arcor.de/eldur/bilder/abweichung1.jpg

I made an xls diagram with the data:

http://home.arcor.de/eldur/bilder/abweichung.jpg

Interesing point here: The further the bullet travels, the more it will deviate from it's original course. Even the 108 is quite precise at 100m (there was no 100m value, but the bump in the curve comes from the extrapolation, it should be flatter at that point...), but very shotgun-like at 1000m.

The point in FB is: It's not modelled 103%. We just have this: Every gun has a unique precision value in form of a maximum deviation angle. For example, the 108 has it at 2‚?, the 50 cal at 0.5‚? and such. Now a randomizer just picks an angle between 0 and the max angle and a direction, and then the shell leaves the barrel with that new direction. That means, that basically all guns are undermodelled in precision in ranges shorter than the "calibration range" where the angle was taken, and overmodelled at ranges beyond that. The 108 is that big "sawed-off" where this is most noticeable.

It's a compromise to save CPU handles that makes the 108 worse that it should be at shorter ranges - and I doubt that they'll change it http://forums.ubi.com/images/smilies/16x16_smiley-wink.gif
Because a shorter calibration range - take the max. deviation angle from 100m instead of 500m for example - would overmodel it at anything anything beyond 100m, and it would be as precise as a 103 maybe... or even more http://forums.ubi.com/images/smilies/16x16_smiley-surprised.gif

JtD
02-25-2005, 11:49 PM
Wiley, your deviation is gravity drop plus/minus something. It's not just the guns accuracy.

[time^2 * 9.81 m/s^2] / 2

BBB_Hyperion
02-26-2005, 01:49 AM
Blutarski you need to concern MK103,Mk108 used part of the recoil energy to reload.

Even when Mk108 is accurate at 100 m (or should be) the low v0 speed makes it drop off fast.

So its mainly a short range weapon when it comes to accuracy but for shooting bombers from 500 m range only 3 or 4 hits were needed.

Here is a table showing how many bullets per range are needed for 50 % chance or 95 % chance of downing a 4 engine bomber.

http://www.butcherbirds.de/hypesstorage/njg1.jpg

Enofinu
02-26-2005, 07:18 AM
Blutarsky, Finnish did not have any 30mm cannons in AC:s at WW2, neighter is Hans Dulias an Finnish pilot, sounds German name to me.

LeadSpitter_
02-26-2005, 07:56 AM
oleg said its much too accurate ingame now due the the whining of the german community

Hopefully he makes it less accurate for realism sakes. So this is the new whine going to start make the 108 more accurate?

You guys are really f;%^^en ridiculous.

JG53Frankyboy
02-26-2005, 08:42 AM
<BLOCKQUOTE class="ip-ubbcode-quote"><font size="-1">quote:</font><HR>Originally posted by LeadSpitter_:
oleg said its much too accurate ingame now due the the whining of the german community

Hopefully he makes it less accurate for realism sakes. So this is the new whine going to start make the 108 more accurate?

You guys are really f;%^^en ridiculous. <HR></BLOCKQUOTE>

sry, but, has a german lately stolen a toy of you ?
also this topic:
http://forums.ubi.com/eve/forums?a=tpc&s=400102&f=26310365&m=6011008482

just wondering because of your "anti german" look alike campaign http://forums.ubi.com/groupee_common/emoticons/icon_frown.gif

about the topic here:
leave the MK108 like its is! its realy lethal . and it should not be again a sharpshooter weapon like in original IL2 release, if you can remember.

JG53Frankyboy
02-26-2005, 08:45 AM
<BLOCKQUOTE class="ip-ubbcode-quote"><font size="-1">quote:</font><HR>Originally posted by carguy_:
Naaah I don`t think there`s any need to spoil the MK108 once again.
It has HUGE ineffectiveness problems with bombers.Test it on DB3 you`ll see what I`m saying.

About ballistics I don`t have complaints but seeing a fighter hit with 3 of those monsters smoking I nod me head.IMO the MK108 was best in IL2 v1.20.

Compare it with MK103.If one round makes energy almost 4 times the MK103 round then it should simply tear everything it hits.Again,try this on DB3http://forums.ubi.com/groupee_common/emoticons/icon_wink.gif <HR></BLOCKQUOTE>

the DB3 have a freaking strange DM , thats it ! as other planes too, from all sides.

FliegerAas
02-26-2005, 12:34 PM
MK 108 is fine. No need to change it for me http://forums.ubi.com/groupee_common/emoticons/icon_razz.gif .
@Holzauge: calibration takes place on the ground, so the guns are more accurate than during flight.

HayateAce
02-26-2005, 01:18 PM
"Mk108 is made unhistorically accurate, due to player complaints."

- Oleg Maddox


Yes please Oleg, for our 109-KlownWagon please make more accurate our laser torpedo gun on front so we will feel even more uber than ever.

We lost war, but try to make up for it in fantasy.

http://www.the5and10.com/images/0256.jpg

Hunde_3.JG51
02-26-2005, 02:31 PM
Blutarski, Gottfried Dulias flew for the Luftwaffe (109G-14A/S of JG-53 "Pik As" squadron) on the Western front, and later on the Eastern front where he became a POW.

Look him up here:

http://www.luftwaffereenactors.org/Dulias.htm

I hope to speak with him again this year.

Stiglr
02-26-2005, 07:20 PM
This would likely not be such a burning issue if the 20mm gun worked properly. Most of us would rather have a 200 round clip that was effective than a 65 round clip that's problematic to hit with.

I don't know at what range you guys fire the Mk108, but I don't ever fire outside 150 with that gun, usually closer...sometimes it seems the shells go sideways!! I don't even bother trying to use that gun at any kind of distance. And if you're pulling any G, fuggedaboudit...

Hunde_3.JG51
02-26-2005, 09:06 PM
I usually only have the MK-108 on FW-190A-8/A-9 since I don't fly Bf-109 that much, so I have a pair of them to work with. I have no trouble at all hitting, even at range. Also, I can easily hit with high deflection shots and I don't find them any more difficult than other guns, in fact I find it easier. But again I have pair of them so I can't speak for how hard it is in 109. I also use 500m convergence when taking 108's because I only need one to hit. IMO the MK-108 is the most dominant gun in FB without question. But like I said I feel no guilt in using them because of the ineffectiveness of 151/20.

Stiglr
02-27-2005, 11:10 AM
Hunde wrote:
<BLOCKQUOTE class="ip-ubbcode-quote"><font size="-1">quote:</font><HR>I feel no guilt in using them because of the ineffectiveness of 151/20.
<HR></BLOCKQUOTE>

Crux of the argument right there.

Give us 20mm that work according to the historical record and lots of us 109 jocks will stop using Mk108s so much. Right now, we don't have much of a "choice".

jagdmailer
02-27-2005, 11:59 AM
<BLOCKQUOTE class="ip-ubbcode-quote"><font size="-1">quote:</font><HR>Originally posted by Stiglr:
This would likely not be such a burning issue if the 20mm gun worked properly. Most of us would rather have a 200 round clip that was _effective_ than a 65 round clip that's problematic to hit with.

I don't know at what range _you guys_ fire the Mk108, but I don't ever fire outside 150 with that gun, usually closer...sometimes it seems the shells go sideways!! I don't even bother trying to use that gun at any kind of distance. And if you're pulling any G, fuggedaboudit... <HR></BLOCKQUOTE>

Yes,

And this mostly eliminates 3 Bf 109 variants from my list of choices:

Bf 109K-4
Bf 109G-14
Bf 109G-10

as you are stuck with this unusable gun for Dogfigthing. It is really a travesty that G-10 and G-14 do not have MG151/20 as nose gun default or at least option.

Jagd

LeadSpitter_
02-28-2005, 03:09 AM
Nachtj√¬§ger - Oblt. Rudolf Thun
The following is a letter written in July 1981 to an author of popular aviation publications, by a former member of the German 'Nachtjagd' (night fighter force), Oblt. (Dr.Ing.) Rudolf E.Thun,who ended the war as Staffelkapit√¬§n (squadron commander) of 9./NJG 6, with 7 confirmed victories.

Thanks for your letter of June 22. I am glad to contribute some of my experiences flying the Bf 110G. Naturally, limitations of time and memory will constrain my remarks to not much more than a few flashbacks, and perhaps not always absolutely accurate ones at that.

First a short summary of my World War II service in the German nightfighter corps. I had started the war as an infantry man, but obtained a transfer to the Luftwaffe after the French campaign. I went through officer's school and various training assignments including Fighter School in Ingolstadt and Night Fighter School in Schleissheim near Munich, until I joined II/NJG 5 in early 1943. II/NJG 5 was then commanded by Major Rudolf Schoenert who achieved a total of 64 confirmed kills and is now a Canadian citizen.

After flying a number of day and night sorties primarily in the defense of Berlin with Bf 110 aircraft, I did a stint as a test pilot from the late summer of '43 to early '44. Shortly after my return to combat, I got the assignment as technical officer of III/NJG 5, and we transferred to Hungary and Southern Germany. On 5/10/44 we became III/NJG 6, and shortly thereafter I was promoted to squadron commander of the 9th Squadron, III/NJG 6 which was equipped with Ju 88. From then on to almost the end of the war, I flew Ju 88 aircraft in combat and got credit for 7 confirmed air victories. I usually flew aircraft with the marking C9 + AM.

I believe that Rudi Schoenert was the first who installed fixed, 75 degree elevated cannons with a separate gun sight in his Do 217, and our weapons sergeant Mahle made also the first "Schr√¬§ge Musik" installation in a Bf-110, the plane of Cpt. Wilhelm Johnen. Mahle later pioneered under my direction the first "Schr√¬§ge Musik" in a Ju 88 when I formed 9./NJG 6. This pair of vertical guns permitted a major breakthrough in night fighter tactics since it facilitated a very accurate attack from below where the dark background generally prevented detection by the crew of the attacked bomber.

But now to the Bf 110 itself. With regard to the various sub types of the 110G you are probably well informed. Let me just add a few observations with regard to the variations in equipment :

The 30mm MK 108 was disliked by most experienced crews. First, the muzzle flash was much too blinding for effective use at night, and secondly, the gun spring would not contain the pieces in case of a shell exploding in the barrel. Even though the German 20mm and 30mm ammunition was extremely reliable, the MG FF or MG 151 provided added safety in this respect. Accordingly, the preferred equipment of the G-4 was MG 151's forward and MG FF's for the "Schr√¬§ge Musik". Experienced crews, by the way, never used tracer ammunition.

A few G-4 were delivered with GM-1 boosters, and I was once stuck to fly such an aircraft. (I think this was the G-4/U7). This was a quite useless modification. The added speed was not needed at night, we never had nitrous oxide in the first place, and the reduction to two crew members was a serious handicap, having a pair of eyes less.

During the '43-'44 time span, while flying day sorties against American bombers, we had our 110's armed with four 21cm (8") diameter rockets. These rockets had only an effective range of 800m, flew in a wide spiral, and reduced the performance and handling of the aircraft very considerably. In fact, one of our planes equipped with these rockets and its bulky carrying rack, crashed during the start just by flying into the propwash of the plane ahead.

The ETC 500 bomb carriers were delivered with the planes and kept in the inventory until mid '44. By the time we needed them flying night ground attacks against the Russians we had of course scrapped them and were limited to using gun fire in these ground attacks.

As you probably know, the radar installations and other electronic equipment varied considerably, even within a series. Early G-4's had the Fu G 202 or 212 (Lichtenstein) together with the SN-2, and the antenna polarization varied. Later on, the SN-2 had an adequate minimum range and the Fu G 212 could be eliminated. Only a fraction of the G series was equipped with Fu G 218 Neptun and/or Fu G 350 Naxos Z. I even had some planes delivered with the Fu G 101 (radio altimeter) indicator, but without the transciever, probably because they didn't have any on the production line and did not want to delay delivery.

A short word on the camouflage paint. Contrary to present beliefs, not too much thought was spent on this question. There was a general recognition that a light, mottled gray or blue-gray was hard to see at night, but beyond that, some lowly mechanic with a spray gun usually had a pretty free hand in spraying a pattern to his heart's desire.

Well, how did the Bf 110 fly? I started with an E which was badly rigged and a total dog. The F without radar was probably the best flying 110, fully acrobatic and in some respects smoother than the Bf 109 where the slats made some racket when wringing the plane out fully. The 110F, of course, didn't have the performance of the 109. Once I got a good 110F with a lot of patience to over 11,000m, just for fun.

The 110G-4 was sort of a mixed bag. The aerials, exhaust flame dampers, drop tanks, other paraphernalia and, of course, the excessive weight when compared to the original design, resulted in a very limited performance and handling envelope. Single engine flight was barely possible with full rudder, and in this case the rudder force was extremely heavy and led to rapid fatigue.

On the other hand, visibility was excellent, and the control forces pleasant and well balanced when flying reasonably within the performance envelope. This made the Bf 110G-4 an excellent gun platform, and since speed was of no great importance against bombers, the Bf 110G-4 was a quite good night fighter. I personally, though, preferred the Ju 88. For day sorties, of course, the Bf 110G-4 was completely inadequate, and we paid with heavy losses which forced the termination of day sorties in early '44.

During the period where night fighters were controlled from the ground within the range of ground radar, no serious electronic counter measures were encountered. The limitations were essentially that of the Lichtenstein radar and of team work and skill. During the period of the "Zahme Sau" where the night fighter forces were directed into the bomber stream and followed it through the target area, the success of electronic counter measures by the British was spotty. By that time, the fighter aircraft were equipped with the SN-2 which gave a decent detection range and permitted a skilled operator to distinguish between enemy aircraft and the metal foil curtains they dropped. More effective toward the end of the war were the very powerful airborne jammers the British used, since the long wavelength of the SN-2 made it quite sensitive to jamming. In summary, the electronic counter measures used by the British were never a major deterrent to experienced night fighter crews, but they were probably quite effective against the younger, less experienced crews on which the night fighter groups had to rely more and more.

Finally, a few vignettes on personal experiences, just to give a flavor of that long ago war in the night sky of Germany. Being a night fighter was mostly waiting during the evening and night hours, waiting for the bombers which, as often as not, did not come. Few slept, since scrambling into low clouds at night was a strong incentive to stay alert. So, in quiet nights, you played cards or chess or read a book, and finally went to your quarters at 2 AM or so. Night fighter units were technically as complex as they come and required a lot of detailed supervision. The elder staff officers were often useless. That meant little sleep for technical officers and unit commanders who were also all combat pilots.

A day sortie against American bombers in early summer '43. We - II/NJG5 - scramble about 30 Bf 110's from Parchim and Greifswald and fly toward an assigned rendevous point north of Berlin to pick up our fighter escorts, a group of Bf 109's. We finally see them at the horizon, but when they come closer, they turn out to be a large formation of American P-51 Mustangs. We hastily form a Lufberry circle, but there was nothing which could have saved us from an attack of these far superior fighters. Fortunately, during these first air raids on the German heartland, the Americans were very careful. After circling us for awhile, the Mustangs took off after their bombers without attacking. Saved for another day.

During the American daylight air raids, the German tactical command - the fighter divisions and Luftflotte Reich - was seriously hampered in directing the air battle by a general confusion about the air situation. As a remedy, Bf 110s of a 'destroyer' wing were used for tactical reconnaissance. Unfortunately, every plane was lost to American fighters. When I came back in early '44 to II/NJG5, from a stint as test pilot I volunteered to fly a few of these reconnaissance sorties. I changed tactics and flew very low, thereby avoiding detection. On one of these flights, I caught an American pathfinder, a B-24 Liberator, flying by itself. Since I had to climb up, I had to attack from behind, and with not all that much speed advantage. My 20mm cannons had only an effective range of about 800m against a 1500m range of the very accurate American .50 caliber (12.7 mm) machine guns. It took an eternity to fly through their fire, but I finally got into shooting position and brought this Liberator down in flames, the crew barely having time to parachute. After landing, I counted over 50 machine gun hits in my plane. And none of the other 9 or 10 Bf 110s of our Group which had sortied that day returned. Of course, most crews came back after awhile, parachute under arm. That was the end of the participation of night fighter forces in daylight air battles over Germany.

This was my first day of annual leave, and my bride to be had already left by train. But as a 'Berliner', I scrambled for this British night raid on Berlin. And here I was, flying at 4800m altitude over Berlin, dodging German flak when the little puffs of smoke come too close to the tail, and waiting for the British bombers which are still 10 minutes away. Suddenly, I am engulfed by the brilliant brightness of 5 German searchlights. They don't react to our coded signal flares, and suddenly, 20mm shells impact my cockpit and the left wing - a German night fighter is attacking! (With auxilliary tanks under the wings, the Bf 110 could be mistaken at night by an inexperienced crew for a four-engined bomber). The plane is on fire and we parachute into the darkness. On the ground, the Flak commander is very apologetic, and my Division commander lends me his liaison plane to get a change of clothing and to start my vacation. Never work overtime in combat!!

Mid-'44 in Hungary. The 105th British Bomber Group flew night raids from Foggia, Italy, into southern Germany and provisioned partisan groups in South-east Europe and Western Russia. These British crews were well seasoned and very sharp, but they suffered from obsolete equipment, flying older Halifaxes, etc., and even some Wellingtons. A week ago, over the eastern Alps, I had one of these bombers in my radar, but that fellow got away by diving deep into one of the pitch black valleys, at the risk of slamming into the mountains. Yet over the last few months, we from the III/NJG 6 have extracted a heavy toll from the 105th Bomber Group, just about wiping them out once over. So, they are now attacking our airfield, and we barely got into the air before the bombs fell. My radar doesn't seem to work or is jammed, and I am straining my eyes in vain for a bomber. Suddenly, about 2000m ahead, a tail gunner uses his flashlight for a moment. The rest is easy. Diving under the bomber, until it's dark, large silhouette is directly above me. Then a salvo from "Schr√¬§ge Musik" into the left engines to give the crew a chance to get out - the "Schr√¬§ge Musik" shoots with pinpoint accuracy. That was my easiest kill.

An attack on Vienna. In the South-east, there was little ground radar guidance, so we try to pick up our targets over the bright sky of the raided city, with the fires and the British markers providing an eerie illumination. We got one on our radar, but boy, is that plane fast - it must be a pathfinder Mosquito or Beaufighter. I am releasing the drop tanks and revving the engines way beyond max power to 3100 rpm, and I am holding the speed of the target but cannot get closer. After 10 or 15 minutes I give up, relieved that the engines did not blow up. When I have landed, I discover that the drop tanks are still under the wing. That made for a very unhappy maintenance crew.

Flying at night against the Russians was difficult, since the ground radar net was too sparse to provide much tactical information. The Russians flew infrequent and scattered air raids at night and gave the distinct impression, that they hardly knew where they were going or what they were doing. Moreover, they flew a lot of American Mitchell bombers which could be mistaken, at least at night, for a Do 217, a type which was flown in the east by NJG 101.

I remember the night one of my buddies, a very successful night fighter, reported happily a Mitchell kill, only ot learn to his dismay that he had gotten one of NJG 101's finest. Fortunately, the crew had safely parachuted back to earth. A week later, when I encountered a Mitchell, I looked at the thing at least for 5 minutes and from all sides before I shot it down. But my most difficult kill of a Russian airplane at night was an old, Russian-built DC 3 with rivets as big as on a ship's boiler, a crazy patchw√¬łrk of odd- shaped skin panels, and slow, slow, slow. To stay with it, I had to get the landing gear and flaps down, and I had to shoot it down during weaving passes from behind. Still it felt good that at least once a German night fighter was too fast!

I think we had many more losses through weather, mechanical failures and British night fighters than through the return fire of bombers. I will never forget the crash in Greifswald due to engine failure shortly after lift-off, the roll-over on instruments at a pretty low altitude due to a sudden failure of the auto pilot, the back flip during roll out on a muddy airfield in fog, or the sneak attack of a British night fighter while flying on auto pilot - fortunately, his use of tracer ammunition gave him away in time - or the many bomber and fighter bomber attacks we had to endure on the ground. Still, in this war of individualists, the experienced pilots and crews had a fair chance to survive. The toll taken of the younger, inexperienced crews, on the other hand, was very heavy, and I, for instance, lost all the officers of my squadron during the last few months of the war.

Well, that should suffice to give you some impression of the Bf 110 as a weapons platform and of the battle in the night skies over Germany during World War II.

Sincerely yours,

Dr. Rudolf E. Thun

Courtesy of Russ Folsom

LeadSpitter_
02-28-2005, 03:16 AM
Let's assume that, with the benefit of hindsight, we could specify the ideal gun armament for a Second World War fighter plane. What might it look like?

If the fighter was to have all-round capability, i.e. effective against enemy bombers as well as fighters, then the first conclusion is that explosive/incendiary projectiles were essential. Comparisons between the destructive power of different types of rounds clearly reveal that the blast effect of HE, combined with the kinetic energy of the shell fragments being hurled through the target and the incendiary effect of the chemicals, add up to considerably greater effectiveness in most circumstances than can be achieved by the kinetic energy of solid bullets or AP projectiles.

This places a certain lower limit on the calibre of the gun. HEI projectiles were available in HMG (heavy machine gun: 12.7-15mm) and even RCMG (rifle calibre: 7.5-8mm) but these little bullets could contain only small quantities of chemicals. It was generally concluded that the smallest shell-firing calibre really worth bothering with was the 20mm cannon. This was demonstrated by the Luftwaffe, which much preferred the 20mm version of the MG 151 to the 15mm, despite the higher velocity (and therefore hit probability and armour penetration) of the smaller calibre, and the fact the HE and incendiary versions of the 15mm were available. The Soviet Air Force similarly showed an increasing preference for the 20mm ShVAK over the lighter and faster-firing 12.7mm Berezin.

Powerful HMGs like the Berezin and the .50" Browning were of course far from useless. They remained quite effective against fighters but would probably have found great difficulty in shooting down heavy bombers. The USN tested the 20mm Hispano against the .50", and concluded that the Hispano was three times as effective at normal fighting ranges, even though the gun weighed less than twice as much.

So, the calibre for our standard fighter gun should be 20mm. Even this might not be enough in some circumstances. If it proved necessary to deal with really tough bombers, then the experience of the German and Japanese air forces showed that it was useful to have larger-calibre cannon - ideally 30mm - available as well.

The ammunition

What kind of ammunition characteristics would perform best in these 20mm and 30mm weapons?

Most cannon shells were made by drilling a hole through a solid steel projectile, to make room for the chemical contents. This led to heavy, thick-walled shells which only contained around 8-10% HEI by weight. In a typical 20mm shell weighing 120g, this meant that only around 10g was HEI mixture. The Germans developed a new type of shell made by drawing from a disk of steel, just as cartridge cases are made. These projectiles were thin-walled and much lighter overall, yet had far more room for chemicals. Their large capacity led to them being called "mine shells", or Minengeschoss (M-Geschoss for short). The standard 20mm M-Geschoss weighed only 92g yet held 18-20g of HEI chemicals, doubling the blast/incendiary effect. It was not always better than the traditional heavy shell (it depended on where it hit) but was usually more effective. An additional benefit was that the light weight permitted a higher muzzle velocity, reducing the time of flight.

The light weight also meant that the M-Geschoss slowed down more quickly and had a shorter effective range. This problem was exacerbated by the blunt-nosed profile of the shells, causing high aerodynamic drag. A later version of the 30mm M-Geschoss, the Ausf. C pattern, had a more tapered form with an aerodynamic, bullet-like profile. This was less efficient in weight/HE content ratio, but the shorter flight time and gain in effective range were considered worthwhile.

Our ideal projectiles should therefore be the more streamlined type of mine shells. Although this would be the most effective type of ammunition, a steel-cored API could also be offered, with a matching weight, shape and trajectory. Tracers would not be used, as in a fighter these had more disadvantages (in warning the enemy he was under attack) than advantages. The optimum belt loading would probably be two or three HEI for each API, although more equal proportions would be better for ground attack or anti-shipping strikes.

The 20mm cartridge

The 92g M-Geschoss proved very effective. To carry the same 20g HEI as this, our ideal streamlined mine shell would probably weigh around 105g. The extra weight would help to extend the effective range as well as providing better penetration into the target.

The muzzle velocity would need to be reasonably high in the interests of short flight time (important for scoring hits, especially in deflection shooting) and maximising the effective range. On the other hand, it shouldn't be very high as that would require a bigger cartridge case, a bigger and heavier gun and probably a slower rate of fire. Comparison with other cannon suggest that around 850 m/s would be optimal. A 105g shell at this velocity generates 38,000 joules muzzle energy; by comparison, the 20x110 Hispano generated 47-50,000 joules, the 20x82 MG 151 29,000. If the case diameter was the same as these rounds, at 25mm, then the length would need to be between them, say 95mm. This is virtually identical to the Japanese Ho-5 20x94 round, but the Japanese projectiles were quite short so the overall length of our ideal 20mm cartridge would be greater. The 20x94 only generated 29,000 joules, but it was severely downloaded because of the weak gun action caused by the use of low-grade steels. As a matter of interest, the muzzle energy of our "ideal" round would be almost the same as the Japanese Type 99-2 (20x101RB: 128g at 750 m/s) but this cartridge case was more slender.

Comparing this performance with the calculation of cartridge effectiveness in this ARTICLE shows that it would have a damage effect of 259 for the HE shell, giving a power factor of 26. This compares with 20 for the 20x110 Hispano round.

The 30mm cartridge

Problems were experienced when guns with different ballistics were combined on the same fighter, as the varying trajectories and flight times made it very difficult to score hits simultaneously with the all of the guns. A prime requirement of our 30mm gun would therefore be that the ballistics should be an exact match for the 20mm, to allow both calibres of gun to be used in the same plane. The key to this is the projectile, which must have the same ballistic coefficient. Assuming the aerodynamic profiles are identical, this depends on the sectional density ratio, and the exact match for the 20mm/105g is 30mm/236g. If this was of the same streamlined Ausf.C type, it would probably contain around 50g HE (this compares with 330g/75g HE for the Ausf.C). 236g is lighter than most 30mm shells have been, but not by much.

The muzzle velocity would of course have to be the same as the 20mm, at 850 m/s, generating a muzzle energy of 85,000 joules. This is coincidentally the same as the postwar 30x113B Aden/DEFA round, although that has a slightly heavier projectile at a slightly lower muzzle velocity. By comparison, the WW2-era 30mm were: MK 108 (30x90 RB) 42,000j; MK 103 (30x184B) 140,000j; IJN Type 2 (30x92RB) 66,000j; IJN Type 5 (30x122) 87,000j; and IJA Ho-155 (30x114) 58,000j. As our 30mm gun would have to do about 2.25x the work of the 20mm (the difference in projectile weight) it is reasonable to assume that the case capacity would need to be around 2.25x greater to hold the necessary quantity of propellant. A certain amount of fiddling with lengths and diameters results in a case diameter of 37.5mm for the same 95mm case length as the 20mm round. This is a very rough and ready measure, but looks about right; it is shorter but fatter than the 30x113B, so would have about the same capacity. As it happens, the Ho-155 case (30x114) has exactly this diameter; but again had to be seriously downloaded for the same reason as the Ho-5. The 30x91 case for the experimental Mauser MK 212 (a rival for the MK 108) also had the same diameter, being just a few millimetres shorter, but the shell was seated deeply in the case, reducing the powder capacity and therefore the muzzle energy.

The same calculation of cartridge power gives a factor of 62, compared with 58 for the MK 108 and 99 for the MK 103.

A picture showing what these ideal shells might look like is HERE. The cartridges, from left to right, are the 20x82 MG 151/20 (with the blunt-nosed M-Geschoss), our "ideal" 20x95, the 20x110 Hispano, our "ideal" 30x95, and the postwar 30x86B Aden LV, which was almost identical to the cartridge for the Mauser MK 213 revolver cannon being tested at the end of WW2. As a matter of interest, the 20x95 image is simply the Ho-5 case, loaded with a scaled-down Ausf.C M-Geschoss. The 30x95 image was created by shortening the Ho-155 case and matching it with a shortened Ausf.C.

The Guns

The main restriction is that we can only choose technology which was in use at the time - no revolvers or rotaries! There was still a considerable choice in gun mechanisms, but of course we would only be interested in the most successful, by which I mean the ones which could deliver a high rate of fire with reasonable weight. The guns would of course be belt-fed. They should also have electrical ignition to facilitate synchronisation.

In 20mm weapons, the best performers were the Soviet gas-operated ShVAK (800 rpm, 42 kg) and Berezin (800 rpm, 25 kg), the recoil-operated Japanese Ho-5 (850 rpm, 35-37 kg) and the hybrid (gas-unlocked delayed blowback) Hispano Mk V and US M3 (750 rpm, 42 kg). The recoil-operated MG 151 could also manage 700-750 rpm from 42 kg, but the Hispano could be speeded up significantly; Molins demonstrated a version firing at 1,000 rpm, but it was not produced because too many parts were different. The Ho-5 was basically a copy of the Browning M2, which also demonstrated its ability to be speeded up, to 1,200 rpm in the M3 version. So our best choice of action seems to lie between the Hispano and the Browning.

The Hispano was a slim gun, well suited to engine mounting. As used in WW2, it fired from a rear sear (open bolt) and could not be synchronised, but electric priming would resolve this problem. The Browning receiver was relatively bulky by comparison, a problem in larger calibres. The Browning was significantly more reliable, but it appears that it relied on some high-stress components in the mechanism (which is why the Japanese had to reduce the power of the larger versions) and it may be significant that despite experimenting with various types of aircraft gun, the Americans never seem to have considered developing a version of the Browning with a calibre larger than 12.7mm. There also seemed to be problems with synchronising the big Browning (its rate of fire dropped by around 30-50%) and it is not clear that electric priming would have resolved them. The best choice would therefore seem to be the speeded-up electric Hispano.

Looking at the performance of the WW2 guns, it seems reasonable to expect our 20mm "electric Hispano" to be capable of firing at 750 rpm at the beginning of the war, increasing to 1,000 rpm by making detailed improvements. Our ideal gun could be shorter and lighter as well as faster-firing than the actual Hispano, as the cartridge is shorter and less powerful, so it should weigh around 35-40 kg. Overall, our 20mm gun/ammunition combination would not be radically better than the MG 151, HS 404, ShVAK or Ho-5 (given good quality steels) but would combine the best aspects of all of them.

Comparing this performance by using the Gun Power and Efficiency calculations (in the article already referred to) reveals a power factor of 325 (at 750 rpm), rising to 433 (at 1,000 rpm). This compares with 200 for the Hispano Mk.II and 250 for the Mk.V (the best of the wartime 20mm guns). The combination of advantages multiply to make this much more effective overall than any other gun in its class. Efficiency is also high; the weight (37.5 kg assumed) giving calculated figures of 8.7 rising to 11.5. This represents a considerably superior power-to-weight ratio to any actual WW2 gun except for the MK 108 at 9.7.

The 30mm cannon should use the same action. In fact, as the cartridges are little different in overall length, the bigger gun would be a similar length but somewhat fatter and heavier. The rate of fire should be 600 rpm initially, with 750 rpm available later, to provide reasonable hit probability. Extrapolation from actual guns indicates that this should have been achievable. There are no close matches with our "ideal" gun - there were very few 30mm cannon - but the closest actual match was the IJA's Browning-type Ho-155, which fired at 450-600 rpm and weighed in at 60 kg. The IJN's Oerlikon-pattern Type 2 weighed 42 kg, although it only fired at 400 rpm. The short-barrelled German MK 108 weighed 60 kg and fired at 600 rpm. On balance, a target of 60-70 kg looks entirely achievable.

Overall, we have a reasonably compact and light gun which due to its lighter shells is a bit less destructive against bombers than the MK 108 but is far better against fighters because of its much higher muzzle velocity, and is therefore a better all-round compromise. The calculations of gun power reveal figures of 620 (at 600 rpm) rising to 775. This compares with 580 for the MK 108 and 693 for the MK 103. The efficiency figures are also excellent, as would be expected: at an assumed weight of 65 kg, the scores are 9.5 rising to 11.9. This compares with 9.7 for the MK 108 and 4.9 for the MK 103.

Mountings

How should our matched 20mm and 30mm cannon be mounted on a fighter? Obviously, there is no problem with twin-engined planes, but the usual choices occur with single-engined fighters. The assumption is that an ideal fighter will have a front engine, as all successful WW2 fighters had this. Different gun installation solutions would be possible with liquid-cooled V-12 engines as opposed to radials.

To start with vee-engined planes: the mounting options for this category of fighter are: in the wings (outside the propeller disk); in the wing roots (inside the propeller disk, so must be synchronised); in the engine cowling (ditto) and engine-mounted to fire through the propeller hub.

The usual RAF/USAAF preference was for outer-wing mountings, which would imply four 20mm or two 30mm and two 20mm. However, the engine-mounted option was such an ideal location for a powerful gun that it seems a shame to waste it. Because it was so good, the gun mounted there should be as powerful as possible, so a 30mm engine cannon should be standard on our fighter. This in combination with a pair of 20mm should give enough firepower for most purposes, so where should the 20mm go?

Mounting them in the engine cowling had the advantage of concentrating the guns close to the longitudinal axis, so improving the concentration of fire at all ranges and helping the roll rate. However, it required the complication (and slightly reduced rate of fire - by about 10% for electric priming) of synchronisation, tended to spoil the aerodynamics of the closely-faired cowling, concentrated the weights too far forward and possibly put the guns in competition with the engine cannon for ammunition space. The wing-root mounting avoided most of these problems while still keeping the guns concentrated.

The outer-wing mounting avoided the need for synchronisation, but made harmonisation (i.e. adjusting the guns to hit one point) more of a problem, as well as spreading the weight across the wing and possibly harming accuracy through recoil-induced wing-flexing. It may be significant that when the Fw 190 had its armament reduced from the usual four 20mm wing-root and outer-wing guns, it was the outer-wing ones which were deleted. All of this suggests that the wing-root mounting offers the best balance of advantages, given an efficient synchronisation system.

This armament of one engine-mounted 30mm and two wing-root 20mm was identical to one of the last and best of the great Fw 190 series, the Ta 152H-1. However, the MK 108 and MG 151 combination in the German plane were poorly matched and of much less use against fighters. If our ideal plane needed more firepower, it would of course be simple enough to add a pair of outer-wing 20mm, and/or to replace the wing-root 20mm with 30mm. The Luftwaffe found problems in synchronising the big MK 103 despite its electric priming, but that had very large cartridge cases which may have caused uneven propellant burning.

In radial-engined fighters, the engined-mounted location would of course not be available. However, the engine layout usually meant more room for cowling mounted guns without hurting the aerodynamics (the Soviets mounted up to four cannon in the cowling). Bearing in mind ammunition weight considerations, the best armament combination might therefore have been two cannon in the wing roots with two in the cowling. This would have delivered a 10% lower volume of fire than outer-wing mountings, but the concentration of fire at all ranges would have more than compensated for that.

LeadSpitter_
02-28-2005, 03:22 AM
The german perspective

The Luftwaffe came to know the Boeing B-17 Flying Fortress intimately. In the air they credited it with speed, load carrying, ruggedness and bristling defensive firepower. Based upon the principle that shooting down a single engine fighter gained the victor one point, the downing of a four-engine bomber was scored as three points. Two points were awarded for damaging a heavy bomber sufficient to force it to leave the safety of the combat box, what the Luftwaffe called "Herausschuss", literally meaning "shooting out." Only one point was awarded for "endgultige Vernichtung" (i.e. the final destruction) of a bomber that had become separated because this task was considered less hazardous. In the end, the Germans shot down over 4000 Flying Fortresses in combat.


At first, American heavy bombers flew in combat boxes of 18 aircraft with succeeding boxes following 1.5 miles behind. To improve the defensive formation, this was replaced by the wing formation that combined three 18-plane groups. Also, instead of flying behind each other, the groups were positioned at high, medium and low level. The medium altitude group would fly slight ahead in the lead with the high squadron above and to the right while the low squadron beneath and on the left. The resulting 54 plane formation occupied a stretch of sky 600 yards long, a mile or so wide and half a mile deep. Other wings might fly identical formations to the target at six-mile intervals.



The B-17 bristled with firepower. A combat wing of 54 aircraft, each carrying about 9000 rounds of ammunition, could bring to bear 648 50 cal machine guns firing 14 rounds a second with an effective range of 600 yds. The two-ounce bullets remained lethal against a human body at ranges up to 4 miles.



B-17‚‚ā¨ôs had surprising little protective armor. Besides the armored seat backs, only the metal surrounding the waist gun cutouts and the bulkhead dividing the top turret gunner‚‚ā¨ôs compartment from the bomb bay were reinforced with steelplate. The firewall dividing the cockpit from the navigator‚‚ā¨ôs station was slightly reinforced but the nose section did not even have a steel deck for the bombardier.

A B-17 formation, dubbed a "Pulk" (herd) by the Germans, was an unnerving sight for the novice sight for fighter pilots. With a combined closing speed of 500 mph both sides had only seconds to make their fire count. Barreling in at 200 yds per second a fighter pilot might have time for only a half-second burst before taking evasive action.



"Fips" Phillips, a 200+ Eastern Front Ace wrote the following while in command of JG 1 defending against American Bombers over Northern Germany:

"Against 20 Russians trying to shoot you down or even 20 Spitfires, it can be exciting, even fun. But curve in towards 40 fortresses and all your past sins flash before your eyes."

The B-17‚‚ā¨ôs most vulnerable quarter of attack was from head-on, at least until the advent of the G-model with its twin gunned chin turret. The next best option was straight down from directly above and a bit behind but this technique called more precise flying. After mid 1944 there was an ever-decreasing number of Luftwaffe pilots who were cable of such precision on a regular basis.



To reliably destroy a B-17, the attacker had to either break the integrity of the flight deck or explode the bombs in the bomb bay. Anything less only damaged the bomber. Hits on less vulnerable areas like the massive vertical stabilizer and rudder might cause the aircraft to slow but it would struggle on. Consolidated B-24 Liberator‚‚ā¨ôs had a tendency to explode when hit but the B-17 rarely did.

Attacking a formation of American bombers from the rear was foolhardy due to the coverging fire from the bomber‚‚ā¨ôs tail and ball turret gunners. Tail attacks also exposed the fighter pilot to additional fire due to the reduced closure speed. The standard fighter approach from 1000 yards astern with an overtaking speed of 100 mph took over 18 seconds to close the distance down to 100 yards.

Initially, head-on attacks were conducted with a flat angle of attack but this made judging the range to the target very difficult. German pilots were initially intimidated by the Fortress‚‚ā¨ô 104 ft wingspan. The urge to open fire from too far away and the breakaway too soon for fear of collision looming large in the gunsight was overwhelming. Further refinement of the tactic showed that the optimum angle of attack when approaching from head-on was from ten degrees above the horizontal, what American bombers crew‚‚ā¨ôs came to call "12 O‚‚ā¨ôclock High." This greatly simplified the problem of estimating range and permitted a constant angle of fire similar to ground strafing.



When intercepting a bomber force, German fighter units initially flew a parallel course off to one side outside the range of the defensive guns. After reaching a point about 3 miles ahead, either three or four plane groups peeled off and swung 180 degrees around to attack head-on in rapid succession. It was critical for the fighters to maintain some semblance of cohesion, or at least visual contact, so after each pass they could regroup for repeated concentrated attacks. That was the theory anyway. In reality, many pilots ended the first pass with a split-S maneuver, inverting and diving down and away from the defensive fire above them.

With increased experience, German fighters began to make their head-on attacks using either in line astern or with the entire unit spread out abreast in the "company front" formation. The recommended procedure was to pull up and over the bombers and then from their position of advantage above, the German fighters were quickly able to launch another attack. It was critical for the fighters to maintain some semblance of cohesion, or at least visual contact, so after each pass they could regroup for repeated concentrated attacks. That was the theory anyway. The huge tail fin of the Fortress posed a collision risk and many German pilots preferred to break away below. Either they dipped the noses of their aircraft and passed close underneath, or rolled inverted and broke hard down with the "Abschwung" (Split-S maneuver.) This took them well below the bombers and valuable minutes were lost before they could gain sufficient height to attack again.

Lt Franz Stigler, a 500mission veteran describes a 1944 attack against American bombers in the excerpt below:

"It was early 1944 and an unescorted formation of about 100 B-17‚‚ā¨ôs came up from the Mediterranean to bomb Germany. Our group of 36 aircraft was ordered off to intercept with my squadron flying high cover to ward off any escorting fighters, while the other two went after the bombers. We made contact just north of the Alps, a few miles from Munich.

We had a good chance to inflict maximum damage to the Fortresses below us and I led my 12-plane squadron down in a screaming dive. We flashed past the high combat box in an overhead pass, continuing through through in a breakaway before climbing back up for another attack.

With high speed built up in a dive, my aircraft made aircraft made a very fleeting target and the more vertical my descent, the more difficult it was for the top turret gunner to get an angle on me. I targeted the pilot‚‚ā¨ôs cabin, the engines and wing‚‚ā¨ôs oil and fuel tanks. On this type of approach, the firing time was extremely limited. I could get in only one short burst. But I was going so fast that I was also harder to hit and the real danger was that I might collide with my quarry. I was through the formation before he even saw me and climbing back for another pass."

Attacks from above had the advantage of placing the vulnerable oil tanks (inside of the inboard engine nacelles) and wing fuel tanks (inside the outboard engine nacelles) directly in the attacker‚‚ā¨ôs path.

By the summer of 1943, the Germans had deployed the Focke Wulf FW 190A4, a dedicated bomber killer armed with two 7.9mm machine guns and four 20mm cannons. With all guns functioning, a three-second burst fired about 130 rounds of ammunition. The Luftwaffe estimated that it took an average of 20 hits from the 20mm cannon to destroy a B-17. Analysis of gun camera film revealed that the average German pilot scored hits with only 2 percent of the rounds fired, thus on average, 1000 rounds were fired to score the 20 hits required.



Seeking to stem the armada of Allied bombers, the Germans tried dropping pre-set bombs on them timed to explode when they were at the same height as the stream. The Germans also employed 210mm, tube-launched, spin-stabilized rockets employing 248-pound projectiles with 80-pound warheads (a version of the German Army‚‚ā¨ôs "Nebelwerfer"). The warheads were time fused to detonate at between 600 to 1200 yds from the launch point. To inflict damage the rocket need only explode within 50 ft of the target although the warhead would also detonate if it struck a bomber. Often an exploding B17 caused enough damage to adjacent planes to bring down another or even two. Although not particularly accurate, the rockets served well to break up the formation. The added weight and increased drag of the installation severely degraded the performance of the German fighters and made them vulnerable to Allied fighter escorts.

With the advent of American long-range fighters, the Germans were forced to change tactics again. They need to inflict damage on the bombers was ever increasing and to accomplish this their planes needed additional and heavier armament. The weight of these additions decreased the performance of their fighters such as to make them easy victims if Allied Fighters were encountered. The Luftwaffe answer was the "Gefechtsverband‚‚ā¨ô (battle formation) consisting a "Sturmgruppe" of heavily armored and armed FW-190A8‚‚ā¨ôs escorted by two "Begleitgruppen" of light fighters, often Bf 109G‚‚ā¨ôs. The task of the light fighters was to engage the escort while the heavy fighters attacked the bombers. It was a great theory but difficult to employ. The massive German formations were unwieldy and took time to assemble. They were often intercepted by Allied Fighters and broken up before they reached the bombers but when they did make it through the results could be devastating. With their engines and cockpits heavily armored, the Sturmgruppen pilots braved the storm of fire and attacked from astern.

Later in the war, the Germans introduced the Mk 108 30mm heavy cannon capable of firing 600 11-ounce high explosive rounds per minute. Three hits with this weapon were usually sufficient to bring down a Flying Fortress. On the other hand it was a low velocity weapon and its effective range was shorter than the 20-mm cannon forcing German pilots to fly even closer to get hits.

The jet propelled Me 262 introduced in the last year of the war was 100 mph faster than contemporary piston-engine fighters and well armed with four 30mm cannons. In a head-on attack, its 350 yards per second closing rate was too fast to allow accurate aiming or to allow optimum use of its short-ranged armament. To overcome this, German Jet pilots used the "roller coaster" attack. Approaching from astern at about 6000 ft above the bombers, the jets pushed over into a shallow dive starting about 3 miles away. They quickly built up speed such that the escorts could not follow them. Diving down until they were about a mile behind and 1500 ft below, they pulled up sharply to bleed off speed, leveling off at 1000 yds astern in position to deliver an attack.

Desperate to inflict massive losses on the American Bomber stream and force a month long bombing pause, the Germans concocted a plan for a massive ramming attack. Late in 1944, Oberst Hans-Joachim Herrman proposed using 800 or so high altitude Bf-109G‚‚ā¨ôs stripped of armor and armament to reduce weight for such an attack. Lightened in this manner, he calculated the planes could reach 36,000 ft well above the American escort fighter‚‚ā¨ôs ceiling. German pilot losses were predicted to be around 300, more or less what was lost in a normal month‚‚ā¨ôs fighting. Aircraft losses would be much higher of course, but by this point numbers of aircraft were not the Luftwaffe‚‚ā¨ôs problem. Trained pilots and especially fuel were. Fully trained fighter pilots were too valuable to be wasted in these attacks, so volunteers were called for from the training units. The first ramming unit, "Sonderkommando Elbe" formed in April 1945 and flew a single mission with 120 aircraft. Its inadequately trained pilots were unable to inflict much damage. Fifteen bombers were rammed but only 8 were destroyed.



References:

Fw 190 Aces of the Western Front by John Weal. Osprey Aircraft of the Aces No.9

Fighter Pilot Tactics by Mike Spick Stein and Day Publishers 1983

Aircraft Versus Aircraft by Norman L.R. Franks Macmillan Publishing Company 1986

LeadSpitter_
02-28-2005, 03:24 AM
sum it up for you guys? Or can we talk about how much airspeed a 2 second burst of 108 cannon should bleed 30kmph airspeed off of a 109g. Thats the same reason why the me262 had to have 3 mile alt advantage and only able to fire in a dive.

Skalgrim
02-28-2005, 05:04 AM
i have oleg declaration, he say in italy,

the p47 have 7 to 1 overrated, that means most american p47 aces are not aces, lol

JG53Frankyboy
02-28-2005, 05:17 AM
<BLOCKQUOTE class="ip-ubbcode-quote"><font size="-1">quote:</font><HR>Originally posted by LeadSpitter_:
sum it up for you guys? Or can we talk about how much airspeed a 2 second burst of 108 cannon should bleed 30kmph airspeed off of a 109g. Thats the same reason why the me262 had to have 3 mile alt advantage and only able to fire in a dive. <HR></BLOCKQUOTE>
where do you read above that the Me262 was only able to fire in a dive because otherwise it would oolse to much speed because of recoil ?

actually there is written that the LOST speed before shooting !
"The jet propelled Me 262 introduced in the last year of the war was 100 mph faster than contemporary piston-engine fighters and well armed with four 30mm cannons. In a head-on attack, its 350 yards per second closing rate was too fast to allow accurate aiming or to allow optimum use of its short-ranged armament. To overcome this, German Jet pilots used the "roller coaster" attack. Approaching from astern at about 6000 ft above the bombers, the jets pushed over into a shallow dive starting about 3 miles away. They quickly built up speed such that the escorts could not follow them. Diving down until they were about a mile behind and 1500 ft below, they pulled up sharply to bleed off speed, leveling off at 1000 yds astern in position to deliver an attack."

and recoil is programmed, fire weapons standing on the ground. sure, dont know if it have an affect on spped while flying.

p1ngu666
02-28-2005, 08:28 AM
it does slow u down if u fire while flying
does on russian aircraft anyways http://forums.ubi.com/images/smilies/16x16_smiley-wink.gif

when u land if u fire u slow down quicker, but u haveto be careful now as 20mm or more makes craters on runway..

BBB_Hyperion
02-28-2005, 09:07 AM
Copy & Paste isnt enough be sure. Actually you need to read and understand the text as well .)

Small Notes
The Ammo & Gun Comparison is missing a major point the explosive used is different and its effect too.

Looks like the book from Anthony G Williams the weapon part i mean. The rating for Mg151/20 is little less than the Hispanio after including chemical power in one of his later publications.

Special for LS a 2 s burst with a gun that fires 600 rpm / 750 rpm makes 20 /25 rounds. With Nose mounted mk108 on g this is just pure nonsense as the vibration spoils aim so dramatically that only the first 4 or 5 rounds are within target zone except it is a barn. A 2 s burst is not desired when useing mk108.

Recoil effect is modeled and as far as i know the amount of speed bleeded depends on many factors such as speed , alt , muzzle energy , engine power etc so how you can come to a conclusion that the answer is 30 km/h ?

The idea for the 262 to slow down is to have more time on target nothing else cause the closing speed is too fast as you can read in the article itself. When your theory that the muzzle flash would significant slow down the 262 would be true the tactic would be to go in fast and get out slow but that isnt the case.

BlackStar2000
02-28-2005, 01:35 PM
S!


Later in the war, the Germans introduced the Mk 108 30mm heavy cannon capable of firing 600 11-ounce high explosive rounds per minute. http://forums.ubi.com/images/smilies/blink.gifThree hits with this weapon were usually sufficient to bring down a Flying Fortress. On the other hand it was a low velocity weapon and its effective range was shorter than the 20-mm cannon forcing German pilots to fly even closer to get hits.


I NEVER, NEVER SAW THAT IN THIS GAME, TAKES MORE THEN 3 MK108 TO SHOOT DOWN A FIGHTER.
ITS VERY RARE MOMENT WHEN A FIGHTER GET DOWN WITH LESS...

jagdmailer
02-28-2005, 03:07 PM
<BLOCKQUOTE class="ip-ubbcode-quote"><font size="-1">quote:</font><HR>Originally posted by LeadSpitter_:
sum it up for you guys? Or can we talk about how much airspeed a 2 second burst of 108 cannon should bleed 30kmph airspeed off of a 109g. Thats the same reason why the me262 had to have 3 mile alt advantage and only able to fire in a dive. <HR></BLOCKQUOTE>

All I know is that I cannot hit $hit with the Mk108 when dogfigthing. I do OK with is against bigger more stationary targets such as B-17s & other medium bombers.

In dogfighting, I much prefer the MG151/20 motor-kanone, and this is why I stay away from Bf 109G-10/G-14/K-4 for dogfigthing. Do not know why we do not have MG151/20 for G-10/G-14 though. I find the Hungarian excuse for the G-14 somewhat pathetic.

Jagd

p1ngu666
02-28-2005, 03:59 PM
try a shorter convergance jagd

onwhine guns do less damage. also think about wanted a lazer torpedoe, thats dead acurate, and fires 10times a second, thats insta death for anything it hits...

whats this? EVERY mk108 plane is flying past la7, ki84c on its way to omgubern00bplane...

no one is gonna respect u if u fly a plane like that, plus servers will remove it from selection...

stop crying, occasionaly mk108 doesnt kill instantly, occasionaly a il2 lives up to its reputation, but MUCH more rarely..

FliegerAas
03-01-2005, 08:05 AM
<BLOCKQUOTE class="ip-ubbcode-quote"><font size="-1">quote:</font><HR>Originally posted by LeadSpitter_:
sum it up for you guys? Or can we talk about how much airspeed a 2 second burst of 108 cannon should bleed 30kmph airspeed off of a 109g. Thats the same reason why the me262 had to have 3 mile alt advantage and only able to fire in a dive. <HR></BLOCKQUOTE>

That's the stupidest pile of **** I heard in a long time. Thanks for the laugh.

HayateAce
03-01-2005, 08:17 AM
Hmmm,

A gaggle of luftflaggers that can't aim for beans, crying about it to oleg and for the world to see.

Sad.

http://forums.ubi.com/images/smilies/16x16_smiley-very-happy.gif

Enofinu
03-01-2005, 10:51 AM
mk108 kills really rarely enemy fighter with one hit, or with even 2 hits. in online at server where is good connections, ping 16 with no packet loss i still have to hit at least 3 times always when killin enemy with 30mm, and with german 20mm its just annoying, cos enemy doesnt much take damage from mg151/20 hits, its peagun.

LeadSpitter, u once said to me that u have seen video, where there was 2 thick wood blocks or something, that it took some 2-3 hits from 20mm HE ammo to cut it in two, while it took some 200 hits from .50 cal to do the same work. can u somehow post that video somewhere?? or, is it something which is against what u want in this sim and which is not realistic.

LeadSpitter_
03-01-2005, 08:26 PM
it was treetrunks about 1 foot wide, then I had others of a simulated aircraft wing built of wood, i dont have these files anymore, I lost them in a reformat many months ago.

Hopefully someone can post them again, Im almost positive one of the llv34s gave me the clips

Manos1
03-02-2005, 05:35 AM
<BLOCKQUOTE class="ip-ubbcode-quote"><font size="-1">quote:</font><HR>......., u once said to me that u have seen video, where there was 2 thick wood blocks or something, that it took some 2-3 hits from 20mm HE ammo to cut it in two, while it took some 200 hits from .50 cal to do the same work. can u somehow post that video somewhere?? or, is it something which is against what u want in this sim and which is not realistic. <HR></BLOCKQUOTE>

I would like to have that video, too.

Meanwhile, here are the photos...

http://astc.de/temp/MK108againstSpitfire.bmp

http://astc.de/temp/mk108_blenheim.jpg

The impact of one (1) grenade (it was an explosive shot). Test fired by RAF if I remember well (static test).

Also a photo of the MK108 gun (notice how short the barel was).

Nubarus
03-02-2005, 05:58 AM
Manos1, in those tests the shells where not fired but placed inside and then remotely detonated.

So the outcome is different then when it is actually fired since an explosion in an enclosed environment is more powerful then an impact explosion on the outside.

Atzebrueck
03-02-2005, 06:05 AM
They didnt detonate outside or right after impact.
The fuze delayed the explosion so that the results should be quite similar to the outcome of this test.

p1ngu666
03-02-2005, 06:56 AM
apart from a hole it made on the way in would decrease pressure abit...

remmber all guns are less effective onwhine, and difference between 2 and 3 rounds is 1oth of a second http://forums.ubi.com/images/smilies/16x16_smiley-wink.gif

WWMaxGunz
03-02-2005, 07:30 AM
High explosive blast damage is not pressure like compressed air from a tank.
That is low explosive mechanism. High explosive blast is a shockwave at many mach
and the air in front of that first hits with equivalent pressure and then pulls back
and forth in a short, hard vibration weakening with every reverse for few reverses.
That first outward hit is enough for light things.

That hole from going in would only weaken the skin on that side. Those shockwaves
hit at between 7 and 1 mach depending on distance from shell and power of explosion.

Same shock inside enclosed space at at the right distances being critical, shockwaves
reflect partly from surfaces (what doesn't transmit through) and reinforces waves on
the other side of the explosion in interference pattern that does multiply the effect.
That is called mach stem and was first understood with nukes but later with shockwaves
from explosives and applied to the Pan Am investigation.

To get mach stem, the shell has to explode in a space right for the size of the explosion
and at a distance also right for the explosion. The British tests shown in the picture
had the shell hanged about where it would be on 90 degree deflection hit maybe? So don't
expect the same results from a rear aspect shot but close from rear quarter maybe?

People who use dynamite know you can be safe close to the blast or you can be missing
parts or dead. There is the well known trick of that where the guy sits over dynamite
but he is in a box and it is too, the dimensions control the shockwave and where he is,
the waves cancel enough he is not hurt instead of a pulse going through him that would
turn his soft tissues (nerves) to jelly.

No combat flight sim can model all that yet.

Enofinu
03-02-2005, 11:30 AM
where it is said that round was placed inside the fuselage on those tests? gather some proof for that before claiming such.

p1ngu666
03-02-2005, 12:10 PM
<BLOCKQUOTE class="ip-ubbcode-quote"><font size="-1">quote:</font><HR>Originally posted by Enofinu:
where it is said that round was placed inside the fuselage on those tests? gather some proof for that before claiming such. <HR></BLOCKQUOTE>

the blast has pushed the sides out equaly, there isnt a entry wound, and firing high explosive rounds at something it may well bounce off and go who knows where, isnt a very good plan tbh.

WWMaxGunz
03-02-2005, 05:19 PM
<BLOCKQUOTE class="ip-ubbcode-quote"><font size="-1">quote:</font><HR>Originally posted by Enofinu:
where it is said that round was placed inside the fuselage on those tests? gather some proof for that before claiming such. <HR></BLOCKQUOTE>

Check with Butch. That picture and the information of how the round was used has been
posted on many WWII air combat sim forums for years with always I've seen being confirmed.

Consider that where exactly the shell explodes depends on speed after penetration, so
what range and alt (air is thinner with alt, less drag with alt) and did it hit a rib,
how fast the target was, angle of strike, etc+1 all affecting in air performance.
OTOH you can hang it in the best guess place and see what happens.

-sarcasm ON- Surely they placed it in the worst spot and that is the least the shell
would do. On average the whole plane should be little pieces and shockwave felt for
kilometers around from such a huge shell as 30mm mine grenade. -sarcasm OFF-

Nubarus
03-02-2005, 05:48 PM
<BLOCKQUOTE class="ip-ubbcode-quote"><font size="-1">quote:</font><HR>Originally posted by Enofinu:
where it is said that round was placed inside the fuselage on those tests? gather some proof for that before claiming such. <HR></BLOCKQUOTE>

Besides the fact that it is known to plenty of people who are interested in WWII history and weapons it's common sense really.

Maybe you like to live dangerously and perform tests with dangerous substances, tools and/or objects without knowing what effect it might have but sensable people perform tests the safest way possible.

This is what happens when people do tests without thinking about what the results might be.

Warning, nimrod alert (http://www.big-boys.com/articles/bottlebomb1.html)

p1ngu666
03-02-2005, 06:22 PM
<BLOCKQUOTE class="ip-ubbcode-quote"><font size="-1">quote:</font><HR>Originally posted by Nubarus:
<BLOCKQUOTE class="ip-ubbcode-quote"><font size="-1">quote:</font><HR>Originally posted by Enofinu:
where it is said that round was placed inside the fuselage on those tests? gather some proof for that before claiming such. <HR></BLOCKQUOTE>

Besides the fact that it is known to plenty of people who are interested in WWII history and weapons it's common sense really.

Maybe you like to live dangerously and perform tests with dangerous substances, tools and/or objects without knowing what effect it might have but sensable people perform tests the safest way possible.

This is what happens when people do tests without thinking about what the results might be.

http://www.big-boys.com/articles/bottlebomb1.html <HR></BLOCKQUOTE>

Enofinu
03-03-2005, 01:13 AM
are you guys sure that all the skin panels are still intact on the fuselage after the explosion? of course they are bended but looks much that every panel isnt there, some detached, at least it looks like that to me. and, about test method, didnt someone calculate or even prooved that shells exploded bout 16cm after first hit at target, depending about the fuse used in the round.

Finnish did have one cannon, not sure was it 20mm cannon, it was used on fokker or such planes, well, anyway before 109:S came in use of FAF. well, they disliked the cannon cos of really sensitive HE ammo used in it. rounds exploded right away when hitted something, no matter if it was cardboard or such. no penetration at all before round did go off, so they said that it was not effective weapon, that s the reason why they wanted AP ammo for that cannon. it was way different issue with mg151/20, cos fuses were delayed and it really did bite well. one burst and 2 engined bombers went down. -was bit off topic-

anyway, ive been toyin with explosives abit in my life, with military stuff in army as well with illegal stolen dynamite and pentrite before armytime http://forums.ubi.com/groupee_common/emoticons/icon_smile.gif as well with blackpowder bombs i made in empty cartridge shells when was teenager, gotta say, those were like minigrenades, made much fragments, dangerous as hell. one did go off when me and big bro standed right next to it :P bro got fragments from it to his leg, where they still are. glad we didnt lose eyes or even worse. deadly stuff. http://forums.ubi.com/groupee_common/emoticons/icon_smile.gif

WWMaxGunz
03-03-2005, 03:40 PM
Mine shell with delay hits something too solid to pierce and what's it do?
It bounces off and then explodes. Doesn't even explode onto the surface.
That's why the need for AP and HE fragment with higher density/better
penetration.

You guys stood next to a metal shell explosive that was lit fuse?
I had a friend almost as dumb, shot M-80's from slingshot. That only cost
him half his right hand from age 13 on. M-80 is cardboard shell.

Kurfurst__
03-04-2005, 06:36 AM
<BLOCKQUOTE class="ip-ubbcode-quote"><font size="-1">quote:</font><HR>Originally posted by Nubarus:
Manos1, in those tests the shells where not fired but placed inside and then remotely detonated. <HR></BLOCKQUOTE>

According to George Hopp (aka Felix) on LEMB, the test rounds were fired into the fuselages. I`d trust what he says, he is an extremely knowladgeable person, being in 109 business for more than 20 years etc...

In any case, it would make any sense to me why would the brits would test a condition that doesn`t match the real life working mechanism of the round..

WWMaxGunz
03-04-2005, 06:54 AM
Stationary target set on braces with frame stresses of those and was that a
perfect 90 degree shot or just what to assume without information on the setup?

Oh yes, realistic conditions there. Not to say that result shouldn't be part
of the good hits to that place, that plane, just before the rear of the plane
tears off. I doubt if the shockwave would do any crew much good but the plane
is going down in any case. I'd also expect that at perhaps 60 degree or less
strike you would begin to see lesser effects though just where the plane would
be lft flyable I can't say. I've seen damage pics on landed planes that show
surprising strength of structure and sub-structure some planes -- it is beyond
the game I guess. Also given dynamics of shockwaves, smaller spaces will not
have the dimensions to get the sheer area of reinforced waves to make such wide
plane devastating damages... less destroyed however much it is depending on
where is hit on what plane, result is not every hit will be the giant damage
radius sphere of obliteration.

Still many times I have felt that blast damage was underdone before TT posted
those screenshots.

Every other Mk 108 is incendiary. And even after fuses were fixed, mine shells
must strike at appx 30 degrees or more to ignite.

Contrary to some few beliefs... Mk 108 is not 88mm AA equivalent either.

Enofinu
03-04-2005, 09:31 AM
MaxGunz wrote: " mine shells
must strike at appx 30 degrees or more to ignite."

how did you end up on that?
really would like to know.
you think that 30mm ammo was not able to get thru aluminium/wooden skin of aircraft under 30 degree angle? how you think the fuses worked on the shells? impact fuse?

WWMaxGunz
03-04-2005, 05:36 PM
Butch made the definite statement.

There is also the damage at angle and 100m charts that all cut off at 30 degrees for
20mm explosive shells.

The fuse must be struck to a certain amount and angle to ignite. That simple or it
jams. Look inside at the mechanisms with pin, plunger and safety locks. These are
not simple percussion cap on the nose devices. You try and push a pin/shaft through
a hole with sideways force, too much and it will resist stronger than the pin/shaft.

Striking and igniting 30 dgrees between path of travel and surface is really good.
Note that while the mine shells do have flattened noses, they are not total cylinders.
There is some rounding from the outer body up to the flattened nose. Things happen
that not every hit just goes tearing through.

Enofinu
03-04-2005, 06:20 PM
odd claims you make Gunz

p1ngu666
03-04-2005, 11:13 PM
not really
just if the angle is shallow, the round will skip off.

same reason u can skip bomb http://forums.ubi.com/images/smilies/16x16_smiley-wink.gif

still works vs tanks, rounds can bounce off, t34 had that, and i saw footage from iraq, where there was just a slight dent from a rpg or other types of missle.

fuse would haveto be fairly robust, to kope with the forces and heat and pressure. it could well be weak in lateral strength tho.

max gunz does know far more than me, and he his intelligent http://forums.ubi.com/groupee_common/emoticons/icon_smile.gif

Enofinu
03-04-2005, 11:36 PM
so ur saying that aluminium is same as on T-34 front hull ?? or what u claim? if you start to claim that under 30degree hit rounds just bounces off from thin aluminium plate? wow!!

on armor plate rounds might bounce off, again depending which kind of fuse is used on em.

BBB_Hyperion
03-05-2005, 01:56 AM
There is a safety mechanism too . The self destructor . When a mine shell stops to rotate it ignites automaticly. But i have difficulties to find a example where the bullet could get through the alu skin without beeing in the 30 degrees range. 1 example would be that already parts of the airfoil are missing and the mine shell bouncing around in the internals luckily avoiding the 30 degrees angle .)

Badsight.
03-05-2005, 02:19 AM
<BLOCKQUOTE class="ip-ubbcode-quote"><font size="-1">quote:</font><HR>Originally posted by BlackStar2000:
I NEVER, NEVER SAW THAT IN THIS GAME, TAKES MORE THEN 3 MK108 TO SHOOT DOWN A FIGHTER.
ITS VERY RARE MOMENT WHEN A FIGHTER GET DOWN WITH LESS... <HR></BLOCKQUOTE>ha ha

id like to see Hayate_Haters posts if the LW guns actually had thier historical hit-power

would be classic

Enofinu
03-05-2005, 05:16 AM
yea, last night gave some 10 hits on mitchell with 30mm, little smoke it poured and then its super gunner got my engine, well, was stupid cos sitted behing the bomber. but, 10hits with 30mm on twin engined plane.. uhh. distance to it was less than 100m.

p1ngu666
03-05-2005, 08:30 AM
<BLOCKQUOTE class="ip-ubbcode-quote"><font size="-1">quote:</font><HR>Originally posted by Enofinu:
so ur saying that aluminium is same as on T-34 front hull ?? or what u claim? if you start to claim that under 30degree hit rounds just bounces off from thin aluminium plate? wow!!

on armor plate rounds might bounce off, again depending which kind of fuse is used on em. <HR></BLOCKQUOTE>

no
if u hit a hard surface at that shallow a angle, its likely to skip or bounce off.

and if u hit at 30degrees, the thinkness of the alu plate is thicker aswell....

depending where u hit, a b25 can take 10 30mm hits, specialy if its spread out across the plane...

sometimes it just snaps, or if u get a grey fuel leak then u WILL run out of fuel....

if u was flying onwhine, the super gunner was probably human... ai gunners are super useless now.

they fire at things they cant see, and are miles away!

b25 u haveto fly, man the turrets and not do quick or harsh manovers, otherwise ull get the stall of death and flat spin in...

WWMaxGunz
03-05-2005, 08:31 AM
Every other shell is incendiary that historically only ignited when immersed in liquid,
also been discussed since 2002.

Fuse problems are what has been behind most duds since there have been fuses.
Eofinu needs to do some studying and also gain some practical mechanical experience.
Stick a bolt in a through-hole and see if you can push it through with even small
side force. Go ahead. I know a man who based a patent on an application of that.

Kurfurst__
03-05-2005, 10:02 AM
<BLOCKQUOTE class="ip-ubbcode-quote"><font size="-1">quote:</font><HR>Originally posted by WWMaxGunz:
Every other shell is incendiary that historically only ignited when immersed in liquid, also been discussed since 2002. <HR></BLOCKQUOTE>

I cannot imagine a fuse that *only* works when immersed in liquid, but perfectly detonation free if it hits the wing structure.. the 108`s incendinary roudns indeed had a hydrostatic fuse to detonate the round in fuel tanks, but I cannot imagine they would not go off otherwise. Sounds very unlikely.

As for the 30 degree angle to detonate the fuse, i don`t get why you need to mention that specifically related to the MK 108 and mine shells. All fuzes on all shells of all nations have such limitations, do you think a Hispano round detonated at any angle? On my part, I have read british reports that state it`s fuse was rather insensitive, only detonating if hitting thick and hard structures. Just an example.

WWMaxGunz
03-05-2005, 07:04 PM
No I don't think that other shells could or did ignite at just any angle.
But since I can't shell for shell say what angle (may be 35 or 40 degrees)
I wasn't gonna post such. Butch stated the 30 degree for that so I feel
safe to repeat.

Where I got the fuse of incendiary needed immersion in liquid was on the
Rhinemetal (spelled wrong there) site or fansite was linked to back in 2002
when Mk 108 damage was questioned long and hard with so much because of
M2 323 base frame ability to absorb shots (what turned out due to the model
was extra strong there to not crush on landing, tells something good about
the models!). That site said the fuse was such to pass through structure
and still make sure to explode in the fuel tank where it was intended to hit.

Holtzauge
03-06-2005, 01:35 PM
I have been away a week now and that is why I have not had a chance to reply before now. I have really enjoyed reading all the posts about what might affect accuracy and also a lot of interesting posts on mk108 shell effectivness as well.

Having participated for a while now on this forum and sifted through the usual posts about Luftwhining that accompanies posts like the one I made I make the following reflection. It strikes me that most of the "Whining" that is done in this forum is actually "Whine-Whining". Be assured, I do not refer to a lot of good posts questioning LW related data based on sound reasoning. However, as soon as a post is make presenting fact based data relating to LW a/c this is immediately pounced on by a dim wit lobby irrespective of content and labeled as Luftwhining. This small but loud lobby is characterized by a total lack of facts and a lot of unsubstantiated opinions. Mayby I stepped on some toes here, but I just needed to get that out of my system http://forums.ubi.com/images/smilies/59.gif

I would like to return to the accuracy issue since IMHO the topic of shell effectiveness deserves a separate post. Why? because this area is so complex that you can dig up countless eyewitness and paper reports coming to this or that conclusion depending on personal opinions and the test setup. The effect a shell hit will have will depend on so many variables that the effect can best be discusseed in hindsight. I truly enjoy reading all the learned posts on this by people who obviously know what they are talking about but in the end it seems difficult to really prove something and I fear we are left to the opinions of the guys crunching the code.

Now concerning the nose mounted mk108 accuracy. The facts on the table are as some posts point out that we have data showing that the mk108 is more accurate than other installations in ground tests. The substantial argument against an improved accuracy seems to be that while this may be true on the ground, the recoil forces will shake the plane in the air so much that the accuracy modelled in the sim reflects true life. I think this is wrong. Consider that the recoil forces are acting throught the a/c centerline close to the center of gravity. The mk108 is bolted to an engine installation weighing close to 1000 kg bolted to an a/c totaling around 3500 kg. This kind of inertia is not something you shake around easily. I still think the ground test accuracys are in the same ballpark you could expect in the air. Also, if the issue was not how solid the mounting in the plane was but that the whole a/c moved when firing then the a/c would tip over forwards when firing pod mounted mk108. This is not something we see in the sim or think realistic is it?

When considering recoil forces, this should be roughly proportional to the energy contained in the charge to propel the round. Some posts seems fixated by the calibre and assume that a 3cm cannon must automatically have much more recoil than a 2cm. The recoil is the result of the gases expelled when the round leaves the barrel (sort of like a short rocket motor burst) and as Blutarski2004 points out below when comparing muzzle energies, the 41250 Joules for the mk108 compared to 30000 Joules for the 151/20 difference is not that great.

From excellent post by Blutarski2004:

"Your data translate to the following -
Mk108: 100 pct dispersion zone = 3 mils
151/20: 100 pct dispersion zone = 6 mils

Compared to USAF data -
Ms 50cal: 100 pct dispersion zone = 8 mils

The exterior ballistics rule of thumb is that, all other things being equal, accuracy approximately varies inversely with caliber. Your data fit perfectly with this rule.

Also, I'm pretty confident that your data must reflect performance of the guns in an a/c mounting, since IMO much better accuracy should be expected from such guns.

As regards recoil forces, muzzle energy of an individual round is:
Mk108 - 41250 joules
151/20 - approx 30000 joules

For comparison
Mk103 - 119000 joules"

As a note on gun accuracy, german sources state that the actual gun accuracy without considering the mounting is in the order of 0,25% of the distance which means that the mk108 installation is close to what is theoretically possible. This again supports that the solid mounting in the nose provided unparallelled accuracy for the mk108 in the Me109K4, G6/U4 or Ta152.

To answer some the posts making analogues to small arms I can refer to my own army experience. I have experience of the H&K G3 assault rifle and the FN MG both firing the 7.62 NATO round. The G3 is very difficult to fire accurately at full auto while with the MG it's a breeze. Why? Because the mass of the G3 is smaller and the line of recoil is higher than your shoulder which make the rifle lift and veer of to the right. Firing the MG is a pleasure http://forums.ubi.com/images/smilies/59.gif, the line of recoil is straight and the mass is larger resulting in controlled full auto fire. From this bit of IRL experience we can deduce that if the recoil acts close to the CG and if we have a hefty mass then recoil is easier to control.

To round off and not to sound to biased, I'm gonna throw a bone to the WW crowd ( that's WW like in Whine-Whining): While I would expect the mk108 to do some serious damage, the usual explosion resulting from a single mk108 hit seems to be a bit on the steep side. But this is just my subjective opinion, unsupported by any facts http://forums.ubi.com/images/smilies/16x16_smiley-very-happy.gif

karost
03-06-2005, 03:00 PM
Hi, I not good for history information, and I happy to read all this stuff http://forums.ubi.com/groupee_common/emoticons/icon_biggrin.gif

so let me point to other direction in that same picture.

by nature of shooting a moving target with big gun ,there have many factors to have a nice shoot for mk 108 :-

- vilocity bullet speed and ROF
- range of target
- target moving direction
- target air speed
- angle of deflection shooting
- a timing that you decide to pull the triggle ( **** this is most important )

also online bad effect like
- bad ping

I never open fire mk108 if my target is stay over 150 meter
my best range is 50 meter below snap shot when I pull up

for online I see many LW friends shooting empty sky ( not a target) for 70% of their bullet ( 65 round ) http://forums.ubi.com/groupee_common/emoticons/icon_biggrin.gif

do you think there have a difference ? if we have a batter mk 108 ,but still not improve quality of our skills.

but I see no difference
IMHO the current MK108 is good enought for me http://forums.ubi.com/groupee_common/emoticons/icon_biggrin.gif

however, this topic is very interesting for me and I'll keep read the next one with respect

S~

Aaron_GT
03-06-2005, 04:03 PM
At 100m it is perfectly possible for the MK108 to have very low DISPERSION. It is fairly low muzzle velocity and although the muzzle energy is higher than the MG151/20 it isn't that much more. The relatively short barrel could be made stiffer to reduce vibrations without making the weapon excessively heavy. Having low muzzle velocity would make it less than ideal as an anti-fighter weapon, however, due to longer flight times and larger drop over longer distances. This would make deflection shooting much more difficult. As can be evidenced by the higher drop of trajectory for the MK108 the muzzle energy bleeds off pretty quickly (larger rounds tend to bleed it less quickly, but the MK108 fires at a low velocity) meaning that there is more chance for atmospherics to affect the flight as distance increases.

I suppose the comparasion is (taken to extremes) between shooting something with a rifle and firing at something with a mortar. You wouldn't try to fire at a moving target with a mortar, but you might be able to hit an emplacement accurately with one. (The short range example is in effect firing a mortar directly at a target - not something you'd do very often!).

WWMaxGunz
03-06-2005, 05:27 PM
Mk 108 fires 2 different rounds.

HEIT leaves barrel at 500 m/s and weighs 455 gm. That makes one curve of trajectory.
MG leaves barrel at 525 m/s and weighs 330 gm. That makes a different trajectory.
Both leave the same barrel pointing the same but the paths will differ with HEIT being
actual tiny bit lower for a short distance. The place where the paths cross will very
likely be the ideal convergence of those shells, but what is it?

Longer range, somewhere there will be enough seperation that you can make all your
hits with just one shell type or the other. HEIT has the tracer so if you long range
for slow shell cannon are hitting with tracers then you have some likely that none of
the mone shells are hitting at all and time for you to cry boohoo and foul just because
you can't see the non-hits but you can count the hits.

Make the track and play it back with arcade on to count actual MG shell hits. Or just
do what so many do to complain is find something that does not work, do that and post
your results as if that's how it is every time.

LLv34_Stafroty
03-06-2005, 05:28 PM
well, i find mk108 better for fighter vs fighter weapon, as well fighter vs bomber weapon cos at least i can make one pass kills with mk108 which is almost impossible with mg151/20. gotta be **** lucky if you ZnB enemy fighter and use 20mm, and got him with first pass. mostly, its just minor damage to target.

Holtzauge
03-07-2005, 01:27 PM
I think you are mixing apples with pears.

Do you really believe that you would see the diffence in flight paths between shells leaving the barrel at 500 or 525 m/s and the deviating flightpaths due to different shell weights visually? This difference is a second order effect. There is no way you would be able visually (by looking through the sight) to distinguish between the flight paths by looking at the tracer even if both rounds had it. The first order effect is the deviation due to the mounting and recoil.

However, just by looking through the REVI while firing the mk108 tells the story. The tracer equipped rounds are all over the place and if you think the modelled deviation correspond to the Flugzeughandbook values for allowable spread stated in the first post then mayby you need new glasses http://forums.ubi.com/groupee_common/emoticons/icon_smile.gif

Try this out: Fly the Fw 190 D9. Zoom the sight magnification. Fire the 151/20. VISUALLY observe how well the shell paths correspond to the sight line. Now do the same with the mk108. See the difference? Do you think the visually observed dispersion area for the mk108 is around a quarter of 151/20 dispersion area as the IRL data indicates?

I think not.....

<BLOCKQUOTE class="ip-ubbcode-quote"><font size="-1">quote:</font><HR>Originally posted by WWMaxGunz:
Mk 108 fires 2 different rounds.

HEIT leaves barrel at 500 m/s and weighs 455 gm. That makes one curve of trajectory.
MG leaves barrel at 525 m/s and weighs 330 gm. That makes a different trajectory.
Both leave the same barrel pointing the same but the paths will differ with HEIT being
actual tiny bit lower for a short distance. The place where the paths cross will very
likely be the ideal convergence of those shells, but what is it?

Longer range, somewhere there will be enough seperation that you can make all your
hits with just one shell type or the other. HEIT has the tracer so if you long range
for slow shell cannon are hitting with tracers then you have some likely that none of
the mone shells are hitting at all and time for you to cry boohoo and foul just because
you can't see the non-hits but you can count the hits.

Make the track and play it back with arcade on to count actual MG shell hits. Or just
do what so many do to complain is find something that does not work, do that and post
your results as if that's how it is every time. <HR></BLOCKQUOTE>

Holtzauge
03-07-2005, 01:49 PM
I totally agree with you on the point of the mk108 as not being an an ideal fighter/fighter weapon just for the reasons you state. (I think we are in good company here beacase I seem to remember that Erich Hartmann himself advocated more more and lighter armament for fighter/fighter work)

However, while we may think it is fun to do the dogfights, this would be tactically incorrect if you were a German in the Reichsverteidigung flying a K4 since the object is to avoid the escorts an knock down the "Dicke Autos". A fighter tied up in a dogfight with a Mustang is essentially a "soft kill" for the Allies.

The heavy guns reflect the German need to knock down bombers, not fighters.

I'm just trying to get a historically correct shooting mk108 in terms of accuracy. I'm not arguing that it's an ideal gun for fighter work and as I said before, I also am a bit suspicious if it was really as effective IRL in terms of exploding the opposition as it's modelled in the sim but I hav eno proof of that. However, I think the sorces I stated in the first post proves that the accuracy modelling is off.

<BLOCKQUOTE class="ip-ubbcode-quote"><font size="-1">quote:</font><HR>Originally posted by Aaron_GT:
At 100m it is perfectly possible for the MK108 to have very low DISPERSION. It is fairly low muzzle velocity and although the muzzle energy is higher than the MG151/20 it isn't that much more. The relatively short barrel could be made stiffer to reduce vibrations without making the weapon excessively heavy. Having low muzzle velocity would make it less than ideal as an anti-fighter weapon, however, due to longer flight times and larger drop over longer distances. This would make deflection shooting much more difficult. As can be evidenced by the higher drop of trajectory for the MK108 the muzzle energy bleeds off pretty quickly (larger rounds tend to bleed it less quickly, but the MK108 fires at a low velocity) meaning that there is more chance for atmospherics to affect the flight as distance increases.

I suppose the comparasion is (taken to extremes) between shooting something with a rifle and firing at something with a mortar. You wouldn't try to fire at a moving target with a mortar, but you might be able to hit an emplacement accurately with one. (The short range example is in effect firing a mortar directly at a target - not something you'd do very often!). <HR></BLOCKQUOTE>

Blutarski2004
03-07-2005, 01:50 PM
<BLOCKQUOTE class="ip-ubbcode-quote"><font size="-1">quote:</font><HR>Originally posted by Holtzauge:
I have been away a week now and that is why I have not had a chance to reply before now. I have really enjoyed reading all the posts about what might affect accuracy and also a lot of interesting posts on mk108 shell effectivness as well.

Having participated for a while now on this forum and sifted through the usual posts about Luftwhining that accompanies posts like the one I made I make the following reflection. It strikes me that most of the "Whining" that is done in this forum is actually "Whine-Whining". Be assured, I do not refer to a lot of good posts questioning LW related data based on sound reasoning. However, as soon as a post is make presenting fact based data relating to LW a/c this is immediately pounced on by a dim wit lobby irrespective of content and labeled as Luftwhining. This small but loud lobby is characterized by a total lack of facts and a lot of unsubstantiated opinions. Mayby I stepped on some toes here, but I just needed to get that out of my system http://forums.ubi.com/images/smilies/59.gif

I would like to return to the accuracy issue since IMHO the topic of shell effectiveness deserves a separate post. Why? because this area is so complex that you can dig up countless eyewitness and paper reports coming to this or that conclusion depending on personal opinions and the test setup. The effect a shell hit will have will depend on so many variables that the effect can best be discusseed in hindsight. I truly enjoy reading all the learned posts on this by people who obviously know what they are talking about but in the end it seems difficult to really prove something and I fear we are left to the opinions of the guys crunching the code.

Now concerning the nose mounted mk108 accuracy. The facts on the table are as some posts point out that we have data showing that the mk108 is more accurate than other installations in ground tests. The substantial argument against an improved accuracy seems to be that while this may be true on the ground, the recoil forces will shake the plane in the air so much that the accuracy modelled in the sim reflects true life. I think this is wrong. Consider that the recoil forces are acting throught the a/c centerline close to the center of gravity. The mk108 is bolted to an engine installation weighing close to 1000 kg bolted to an a/c totaling around 3500 kg. This kind of inertia is not something you shake around easily. I still think the ground test accuracys are in the same ballpark you could expect in the air. Also, if the issue was not how solid the mounting in the plane was but that the whole a/c moved when firing then the a/c would tip over forwards when firing pod mounted mk108. This is not something we see in the sim or think realistic is it?

When considering recoil forces, this should be roughly proportional to the energy contained in the charge to propel the round. Some posts seems fixated by the calibre and assume that a 3cm cannon must automatically have much more recoil than a 2cm. The recoil is the result of the gases expelled when the round leaves the barrel (sort of like a short rocket motor burst) and as Blutarski2004 points out below when comparing muzzle energies, the 41250 Joules for the mk108 compared to 30000 Joules for the 151/20 difference is not that great.

From excellent post by Blutarski2004:

"Your data translate to the following -
Mk108: 100 pct dispersion zone = 3 mils
151/20: 100 pct dispersion zone = 6 mils

Compared to USAF data -
Ms 50cal: 100 pct dispersion zone = 8 mils

The exterior ballistics rule of thumb is that, all other things being equal, accuracy approximately varies inversely with caliber. Your data fit perfectly with this rule.

Also, I'm pretty confident that your data must reflect performance of the guns in an a/c mounting, since IMO much better accuracy should be expected from such guns.

As regards recoil forces, muzzle energy of an individual round is:
Mk108 - 41250 joules
151/20 - approx 30000 joules

For comparison
Mk103 - 119000 joules"

As a note on gun accuracy, german sources state that the actual gun accuracy without considering the mounting is in the order of 0,25% of the distance which means that the mk108 installation is close to what is theoretically possible. This again supports that the solid mounting in the nose provided unparallelled accuracy for the mk108 in the Me109K4, G6/U4 or Ta152.

To answer some the posts making analogues to small arms I can refer to my own army experience. I have experience of the H&K G3 assault rifle and the FN MG both firing the 7.62 NATO round. The G3 is very difficult to fire accurately at full auto while with the MG it's a breeze. Why? Because the mass of the G3 is smaller and the line of recoil is higher than your shoulder which make the rifle lift and veer of to the right. Firing the MG is a pleasure http://forums.ubi.com/images/smilies/59.gif, the line of recoil is straight and the mass is larger resulting in controlled full auto fire. From this bit of IRL experience we can deduce that if the recoil acts close to the CG and if we have a hefty mass then recoil is easier to control.

To round off and not to sound to biased, I'm gonna throw a bone to the WW crowd ( that's WW like in Whine-Whining): While I would expect the mk108 to do some serious damage, the usual explosion resulting from a single mk108 hit seems to be a bit on the steep side. But this is just my subjective opinion, unsupported by any facts http://forums.ubi.com/images/smilies/16x16_smiley-very-happy.gif <HR></BLOCKQUOTE>


..... Holtzauge, I noticed an error in my statement above. It should read the DISPERSION varies inversely with caliber - i.e., the larger the caliber, the smaller the dispersion.

BTW, I posted the following under another thread, but it bears repeateing here. I finally unpacked the rest of my aviation books and found my copy of German Aircraft Weapons WW1 & WW2. The book contains a photo of what is described as a test of a German 30mm round against what appears to have been a wing from a P40. The 30mm round blew out a complete rectangular hole in the wing, from the joint line where the wingtip attached to the wing inward to halfway along the length of the aileron, and from the joint line of the rounded leading edge back to the hinge line of the aileron. Pretty impressive - everything was blown out: skin, spars, and ribs. I'm assuming that it was an M/Geschoss round from the massive degree of damage.

WWMaxGunz
03-08-2005, 12:32 AM
The difference of 525 and 500 m/s changes with range. Long range it becomes far more.

What I posted is not about dispersion so much as mass spectrometry of shells.
The HEIT shell is half again as heavy as the MG shell. As range increases the MG will slow
far more than the HEIT. Both drop at the same rate but the HEIT will be farther and farther
away for the same drop ***some after the 25 m/s start speed advantage of the MG is lost and
the HEIT catches up***. Looking at ballistics tables, that point occurs before most people
would expect for up to even 20mm. There should be an ideal range where all coincide on drop,
that would be the best convergence and I am sure that cartridge powder behind the MG was
carefully adjusted to create the extra muzzle velocity of that shell just to match such a
point, they could have put more for MG or less for HEIT to tune for the different shell
masses. With the long history of ballistics I would expect no less from German craftsmen.

Dispersion, you can only see the tracers. Check it from grounded planes and look to things
like does this sim model have the shocks and another not, where the gun is, etc.

I think you have an issue about Mk 108 dispersion but visual you can only see the smoke
that came off HEIT. Smokestack time?

Take what I wrote now below and apply it to the grouping of the shots if you may. Long
range which may be 150m+ or 200m+ there should be a mass seperation between HEIT and MG
such that hits with one type should exclude more and more hits of the other. Also if the
nose is swinging as in turn or pitch up, the seperation should be more IMO due to the
acceleration of pitch or turn or both. There are BTW actual devices that seperate particles
in these manners.


<BLOCKQUOTE class="ip-ubbcode-quote"><font size="-1">quote:</font><HR>Originally posted by Holtzauge:
I think you are mixing apples with pears.

Do you really believe that you would see the diffence in flight paths between shells leaving the barrel at 500 or 525 m/s and the deviating flightpaths due to different shell weights visually? This difference is a second order effect. There is no way you would be able visually (by looking through the sight) to distinguish between the flight paths by looking at the tracer even if both rounds had it. The first order effect is the deviation due to the mounting and recoil.

However, just by looking through the REVI while firing the mk108 tells the story. The tracer equipped rounds are all over the place and if you think the modelled deviation correspond to the Flugzeughandbook values for allowable spread stated in the first post then mayby you need new glasses http://forums.ubi.com/groupee_common/emoticons/icon_smile.gif

Try this out: Fly the Fw 190 D9. Zoom the sight magnification. Fire the 151/20. VISUALLY observe how well the shell paths correspond to the sight line. Now do the same with the mk108. See the difference? Do you think the visually observed dispersion area for the mk108 is around a quarter of 151/20 dispersion area as the IRL data indicates?

I think not.....

<BLOCKQUOTE class="ip-ubbcode-quote"><font size="-1">quote:</font><HR>Originally posted by WWMaxGunz:
Mk 108 fires 2 different rounds.

HEIT leaves barrel at 500 m/s and weighs 455 gm. That makes one curve of trajectory.
MG leaves barrel at 525 m/s and weighs 330 gm. That makes a different trajectory.
Both leave the same barrel pointing the same but the paths will differ with HEIT being
actual tiny bit lower for a short distance. The place where the paths cross will very
likely be the ideal convergence of those shells, but what is it?

Longer range, somewhere there will be enough seperation that you can make all your
hits with just one shell type or the other. HEIT has the tracer so if you long range
for slow shell cannon are hitting with tracers then you have some likely that none of
the mone shells are hitting at all and time for you to cry boohoo and foul just because
you can't see the non-hits but you can count the hits.

Make the track and play it back with arcade on to count actual MG shell hits. Or just
do what so many do to complain is find something that does not work, do that and post
your results as if that's how it is every time. <HR></BLOCKQUOTE> <HR></BLOCKQUOTE>

WWMaxGunz
03-08-2005, 12:41 AM
<BLOCKQUOTE class="ip-ubbcode-quote"><font size="-1">quote:</font><HR>Originally posted by Blutarski2004:

the DISPERSION varies inversely with caliber - i.e., the larger the caliber, the smaller the dispersion.

<HR></BLOCKQUOTE>

But only applicable if you include "all other factors equal (or nearly so)".

Larger caliber alone is not a guarantee of less dispersion.

There are also times when the same caliber, different weapons differ in dispersion.

butch2k
03-08-2005, 03:29 AM
As posted on my forums here: http://www.allaboutwarfare.com/forums/index.php?showtopic=492&hl=


---------------
H means Height (or max dispersion diameter) as i previously used vertical and lateral dispersion values.

D means distance.

Units are metric.

German Weapons
-----------------------
MG-17 Cowling mounted (Bf 109F-2 / Bf 109F-1 actual tests)
H = 0.60 / 0.8 m
D = 100 m
R/D = 60/10000 80/10000
= 6 mils / 8 mils

MG-131 Cowling mounted (Fw 190A - theorical max)
H = 1m
D = 100m
H/D = 100/10000
= 10 mils

MG-151/15 Engine mounted (Bf 109F-2 actual test)
H = 0,35 m
D = 100 m
H/D = 35/10000
= 3.5 mils

MG-FF Engine mounted (Bf 109F-1 actual test)
H = 0,2 m
D = 100m
H/D = 20/10000
= 2 mils (very tight patern)

MG-FF Wing mounted (Bf 109E-3 actual test)
H = 0,35 m
D = 100m
H/D = 35/10000
= 3.5 mils

MG 151/20 Engine mounted (Bf 109G-6 - theorical max)
H = 0.3m
D = 100m
H/D = 30/10000
= 3 mils

MG 151/20 Wing mounted - inner (Fw 190A - theorical max)
H = 0.7m
D = 100m
H/D = 70/10000
= 7 mils

MG 151/20 Wing mounted - outer (Fw 190A - theorical max)
H = 0.8m
D = 100m
H/D = 80/10000
= 8 mils

MK 108 Engine mounted (Ta 152 - therorical max)
H = 0.35
D = 100m
H/D = 35/10000
= 3.5 mils

Allied Weapons
------------------
M2 Nose mounted P-38 (USAAF 1944 Gunnery manual)
H = 1.88 m
D = 229 m
H/D = 188/22900
= 8.2 mils (75% = 4.1 mils)

Hispano 20mm Nose mounted P-38 (USAAF 1944 Gunnery manual)
3 mils 75%
6 mils 100% assumed
-----------------

anarchy52
03-08-2005, 03:41 AM
<BLOCKQUOTE class="ip-ubbcode-quote"><font size="-1">quote:</font><HR>Originally posted by BlackStar2000:
I NEVER, NEVER SAW THAT IN THIS GAME, TAKES MORE THEN 3 MK108 TO SHOOT DOWN A FIGHTER.
ITS VERY RARE MOMENT WHEN A FIGHTER GET DOWN WITH LESS... <HR></BLOCKQUOTE>
My personal record is 6 (or was it 7) for a P-38.
Finished him off with 13mm long bursts at left engine nacelle. I think I posted the track on this very forum. Yesterday 3 Bfs shot at B-25 which recieved ~10 mk108 hits and crashed later due to fuel tank leak. On the other hand 2 shvak hits can break the wing of the FW-190...

Kurfurst__
03-08-2005, 03:45 AM
<BLOCKQUOTE class="ip-ubbcode-quote"><font size="-1">quote:</font><HR>Originally posted by WWMaxGunz:
The difference of 525 and 500 m/s changes with range. Long range it becomes far more.

What I posted is not about dispersion so much as mass spectrometry of shells.
The HEIT shell is half again as heavy as the MG shell. As range increases the MG will slow
far more than the HEIT.
<HR></BLOCKQUOTE>

Maybe it`s modelled as such in the game, but the german specsheets I just checked shows the MK108`s and it shows

Minegeschoss shell weighting 330 gram, V0= 500 m/sec, V500m=385 m/sec, t500 = 1.139 sec.

(earlier Ausf. A shells only 294m/sec at 500m, due to worser form)

Brandgranate w. Tracer weighting only 370gram, V0= 485 m/sec, V500m=302 m/sec, t500 = 1.307 sec.

So there was not much difference between the shells themselves.

karost
03-08-2005, 06:32 AM
<BLOCKQUOTE class="ip-ubbcode-quote"><font size="-1">quote:</font><HR>Originally posted by Holtzauge:
2) Ta152 H-0 und H-1 Vorlaufiges Flugzeug-Handbuch, Schusswaffenanlage, Dezember 1944
In both these sources there are parts about how to calibrate the guns.
In ref 2, Schusswaffenanlage, page 40, section 13, the following spread is allowed for the gun installation:

At 100m Mk108: All shells should hit within an area of height 35 cm and width 30 cm.
At 100m 151/20 installation: All shells should hit within an area of height 70 cm and width 60 cm.
In ref 1, for the Mg131 installation in the G6/U4 the accuarcy requirement is height 100 cm and width 100 cm
<HR></BLOCKQUOTE>

WOW ..... Mk108 look like a sniper gun hummm. 100meter is my standard for me for shooting Mk108 if I made point shooting 1 second brush all 6 round of bullet will stay together with in 30cm area...! Oh how much total distruction power will generate ?

but .. I think we miss one thing a sample target is a moving target or non-moving target ? but that is a minimum effect coz, from 100 meter range a fighter is bigger than 30cm about 3-5 times from dead 6 and 10 times for bomber right ?

So only a surprise attack situation that I have a chance to put all 6 round inside a fighter ... well ...I still see there is "no difference" coz, 90% shooting situation need deflection shooting skill and vilocity ( bullen speed ) is big a mojor factors.

most people missing shoot coz velociy (bullet speed) it only 500m/s
this is my very old tutor for teach my friends for deflection shooting MK108 for point out what I meaning http://forums.ubi.com/groupee_common/emoticons/icon_biggrin.gif

http://www.allthaiproperties.com/tempsite/bmax/fb/img/109G6/109DF90_04_A.JPG
http://www.allthaiproperties.com/tempsite/bmax/fb/img/109G6/109DF90_04_B.JPG
http://www.allthaiproperties.com/tempsite/bmax/fb/img/109G6/109DF90_04_C.JPG
http://www.allthaiproperties.com/tempsite/bmax/fb/img/109G6/109DF90_04_D.JPG
http://www.allthaiproperties.com/tempsite/bmax/fb/img/109G6/109DF90_04_E.JPG
http://www.allthaiproperties.com/tempsite/bmax/fb/img/109G6/109DF90_04_F.JPG

first four round miss but last two round hit ( I don't know last 2 round are MG shell or not )http://forums.ubi.com/groupee_common/emoticons/icon_biggrin.gif

if I-16 fly faster than 400km/h so I may shooting an empty sky for sure coz I set at DFR=1.5

** 1 DFR = 9 meter (fighter lenght) **

S~

WWMaxGunz
03-08-2005, 12:56 PM
Good lesson!

Since every other shell is HEIT then MG (if it is still as before in IL2, I make no bets!)
then of the last two, one should be MG.

I find that shooting while pulling up spreads the fire not just space between shells but
over an arc. You might get better to hold flight and place a short stream of fire across
where the target will fly into it if the angle is not unduly wide across his path.
Otherwise, yes follow his move with a sweep and the shells will be effectively closer
together.
I don't practice nearly enough but I still get some of the hits. Once you have a feel for
the fall of the shots I think the trigger finger knows about when to fire.

LLv34_Stafroty
03-09-2005, 11:28 AM
Blutarski, any chanses to post that P-40 wing hit by 30mm at here??

crazyivan1970
03-09-2005, 11:32 AM
You guys are simply amazing.. you managed to generate 5 pages thread on the problem that doesn`t exist http://forums.ubi.com/groupee_common/emoticons/icon_biggrin.gif But regardless,was an interesting read http://forums.ubi.com/groupee_common/emoticons/icon_biggrin.gif

Holtzauge
03-10-2005, 01:51 PM
Crazyivan, what kind of filter did you employ when reading the posts. Dark glasses probably http://forums.ubi.com/images/smilies/59.gif

The IRL data I posted and the execellent data in the post by butch2k (see below) clearly indicates that engine mounted cannon have exceptional accuracy due to the solid mounting (at least the German planes, I have no data on Allied planes unfortunately). The engine mounted patterns are in the order of 2-4 mils spread whereas the wing and cowling mounted dispersions are double or more than that 6-10 mils.

This is modelled in reverse in the sim where just by eyeballing the tracers you can see that in PF wing mounted cannon like the 151/20 and cowling mounted MG like the MG131 and MG17 installations have better accuracy.

Why not reverse the tables? Where is the proof that the PF modelled dispersion patterns are in any way correct?

Is there any data to support this?

I'm waiting..... http://forums.ubi.com/images/smilies/16x16_smiley-happy.gif

Excerpt from butch2k's excellent post:
"German Weapons
-----------------------
MG-17 Cowling mounted (Bf 109F-2 / Bf 109F-1 actual tests)
H = 0.60 / 0.8 m
D = 100 m
R/D = 60/10000 80/10000
= 6 mils / 8 mils

MG-131 Cowling mounted (Fw 190A - theorical max)
H = 1m
D = 100m
H/D = 100/10000
= 10 mils

MG-151/15 Engine mounted (Bf 109F-2 actual test)
H = 0,35 m
D = 100 m
H/D = 35/10000
= 3.5 mils

MG-FF Engine mounted (Bf 109F-1 actual test)
H = 0,2 m
D = 100m
H/D = 20/10000
= 2 mils (very tight patern)


MG 151/20 Engine mounted (Bf 109G-6 - theorical max)
H = 0.3m
D = 100m
H/D = 30/10000
= 3 mils

MG 151/20 Wing mounted - inner (Fw 190A - theorical max)
H = 0.7m
D = 100m
H/D = 70/10000
= 7 mils

MG 151/20 Wing mounted - outer (Fw 190A - theorical max)
H = 0.8m
D = 100m
H/D = 80/10000
= 8 mils

MK 108 Engine mounted (Ta 152 - therorical max)
H = 0.35
D = 100m
H/D = 35/10000
= 3.5 mils
"

<BLOCKQUOTE class="ip-ubbcode-quote"><font size="-1">quote:</font><HR>Originally posted by crazyivan1970:
You guys are simply amazing.. you managed to generate 5 pages thread on the problem that doesn`t exist http://forums.ubi.com/groupee_common/emoticons/icon_biggrin.gif But regardless,was an interesting read http://forums.ubi.com/groupee_common/emoticons/icon_biggrin.gif <HR></BLOCKQUOTE>

WWMaxGunz
03-11-2005, 12:42 AM
Consider the evidence of the .50's in AEP. No matter how mounted, all of them produced
the same disperion. Engine (.50's are on Buffalo and one Italian plane), Canopy, Wing,
all the same. Dispersion was figured by model and then applied but there is one code
for each gun and one only, it appears not just ammo mix.

Airmail109
03-11-2005, 08:07 AM
AHAHAHAHAH u guys say u cant hit anything when pulling G with mk 108s! Bad marksmenship I say! I can consistently hit aircraft at high deflection angles with a short burst from my 108! Only last night a spitfire dived on my buddies.....I pulled a a 90 degree hard turn to left.....pulled lead on him and let loose about 4/5 rounds.........3 of the rounds hit him...one just in front of the cockpit and the other two in his port wing ripping it off! You whiners cant shoot straight thats the problem! http://forums.ubi.com/images/smilies/51.gif

Holtzauge
03-11-2005, 11:02 AM
Geez, I knew the Germans were short on pilots late in the war but I never would have guessed they were desperate enough to train rabbits as Nachwuchs.

However this rabbit not talks the talk and walks the walk. He can pull G's and shoot too!

Bravery on this level definitely entitles you to a carrot with oak leaves.

PS: How do rabbits cope with the 109 elevator model in PF? Do you experience any problems pulling G at higher speeds? http://forums.ubi.com/images/smilies/88.gif

<BLOCKQUOTE class="ip-ubbcode-quote"><font size="-1">quote:</font><HR>Originally posted by Aimail101:
AHAHAHAHAH u guys say u cant hit anything when pulling G with mk 108s! Bad marksmenship I say! I can consistently hit aircraft at high deflection angles with a short burst from my 108! Only last night a spitfire dived on my buddies.....I pulled a a 90 degree hard turn to left.....pulled lead on him and let loose about 4/5 rounds.........3 of the rounds hit him...one just in front of the cockpit and the other two in his port wing ripping it off! You whiners cant shoot straight thats the problem! http://forums.ubi.com/images/smilies/51.gif <HR></BLOCKQUOTE>