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View Full Version : German BoB cannon not up to the job. - official.



Low_Flyer_MkVb
02-09-2006, 03:36 AM
Source: The Guns of the Royal Air Force 1939 €" 1945. G.F. Wallace
William Kimber. London. 1972.
ISBN 7183 0362 8

G.F. Wallace was senior technical officer of the Gun Section of the Directorate of Armament Development.

(Chapter 16: The German Guns.)

€œOur only interest in the German guns was to keep a check on them to see that they did not outclass our own guns; this they never did.€

The Oerlikon 20mm gun.

€œThis was one of the Germans€ big mistakes. It was produced by the Oerlikon Company as an aircraft gun, a smaller, lighter, but supposedly equally effective version of their heavy ground anti-aircraft 20mm gun. The Oerlikon was a pure blowback gun which meant that for a high-powered cartridge the breech block had to be very heavy or to be attached to something very heavy. The anti-aircraft Oerlikon used a cartridge of similar power to the Hispano 20mm. To lighten the gun for aircraft use, Oerlikon reduced the powder charge considerably. This meant that the length of the cartridge was greatly reduced, which in itself meant a shorter gun, and the reduced power of the cartridge meant a much lighter breech block assembly. The length of the barrel was also reduced. All this meant that the muzzle velocity was greatly reduced, but this was considered acceptable for two reasons. Firstly, the gun would only be used at very short range in air fighting, and secondly, as the 20mm shell depended for its€ effect on its€ explosive charge, the velocity on hitting the target was unimportant. The first premise was true enough, but the second proved a complete fallacy €" as was soon proved in the Battle of Britain. Owing to its€ low velocity, the short Oerlikon gun had no greater penetration than the rifle calibre bullet, possibly less.€

€œIn general, the short Oerlikon was no more effective than the rifle calibre gun, so the Me. 109 with its€ two 7.9mm guns and two 20mm short Oerlikon guns was completely outgunned by the Spitfire and Hurricane. Had the Me. 109 been fitted with two guns firing the full-powered anti-aircraft Oerlikon cartridge, the story would have been very different.€

mothyp
02-09-2006, 03:52 AM
tell that to the 590 plus pilots who died during the BoB at the hands of German guns, i understand the article is examing the effectiveness of the 20mm but it only takes one bullet to kill a chap or a shard of glass etc.

nakamura_kenji
02-09-2006, 03:54 AM
japanese navy cannon was Oerlikon 20mm build under liecense but have number modification major one be were modify belt amunition magazine allow much high ammo load compare to 60/100 round drum magazine

early type-99-I(a6m2/3) have poor muzzle speed acuracy becuase barrel were shorten so fit areo dynamic shape of wing. type-99-II(a6m5/n1k2/j2m3) much long barrel give improve acuracy/range/muzzle speed but slight decrease fire rate. easy tell difference type-99-II stick out wing Type-99-I not

http://www.quarry.nildram.co.uk/Oe1b.jpg

Type-99-I 20 x 72RB
Type-99-II 20 x 101RB

http://homepage3.nifty.com/tompei/08-Type99-20mmMG.jpg
type-99-I(drum mag)

http://www.quarry.nildram.co.uk/JOerlikonsa.jpg
type-99-II

StG2_Schlachter
02-09-2006, 04:04 AM
Which 20mm is this reffering to?

MG/FF or MG/FF(M) ?

The Minengeschoss version, although still only effective at short range, was very powerful.

I saw several pictures of Hurricanes with severed wings. I doubt this was done with the 7.9 mm MGs.

The claim, that the Hurricane outgunned the Messerschmitt, is not entirely true.
It had more guns yes. But the article itself implies that rifle caliber rounds had only little penetration ability. Since the cannon armed Hurricane was not used in the BoB this statement should be revised.

panther3485
02-09-2006, 04:11 AM
PHHHHHHHHHHHHTTTTTTTTTTTTT!!!!!!

Hey, Low_Flyer, this isn't some kid of silly joke, is it?

May I suffer and deserve forum embarrassment if I'm wrong, but I'd have to consider myself highly sceptical about this. If the context of what I've read here is what is seems, it sounds like trumpet-**** dribbling for propaganda or morale purposes, more than anything else. In other words, total bovine excrement.

At close range, under almost any conditions, almost any type of 20mm cannon shell would have to be more effective against an airframe than a round of rifle-calibre MG. In general, you don't want 'penetrating power' for best effect. You want 'hitting power', or, if you like, 'weight of shot'. If you can combine that with explosive power, so much the better.

Have I misunderstood the article? If I have, my apologies to the author. If I've read and interpreted it correctly, however, it's sheer ****wipe.


panther3485

JG53Frankyboy
02-09-2006, 04:15 AM
a 20mm MG-FF (not to speak of the MG-FF "M" with its mineshells! ) not more effective than a .303 Browning ?.............................

JG52Karaya-X
02-09-2006, 04:21 AM
Originally posted by Low_Flyer_MkVb:
€œOwing to its€ low velocity, the short Oerlikon gun had no greater penetration than the rifle calibre bullet, possibly less.
In general, the short Oerlikon was no more effective than the rifle calibre gun, so the Me. 109 with its€ two 7.9mm guns and two 20mm short Oerlikon guns was completely outgunned by the Spitfire and Hurricane.

Sorry but that's just BS.

I wonder how the Bf109E could shoot Spitfires and Hurricanes into flames then - must have been those über-Mg17s then http://forums.ubi.com/groupee_common/emoticons/icon_rolleyes.gif

MGFF vs Hurricane
http://rapidshare.de/files/12866932/Spitfire_under_attack.mpeg.html

MGFF vs Hurricane
http://rapidshare.de/files/12866893/Hurricane_under_attack.mpeg.html

He's talking about the lack of penetration power of the MGFF (and /M for that matter) - but completely forgets (or neglects) that the Oerlikon and most other 20mm relied on their HE content for hitting power.

To stay true to this type of thinking: The Mk108 is in effect an up-scaled MGFF with 30mm rounds - low muzzle velocity, low penetration. Now we all know that it was COMPLETELY ineffective against planes http://forums.ubi.com/groupee_common/emoticons/icon_rolleyes.gif

BTW do you prefer trout or salmon?

http://gormanflyfishing.com/images/mckenzie_santiamimages/mandy_joeJensen_one_resampled.JPG

panther3485
02-09-2006, 04:29 AM
In case anyone didn't figure it, my first set of asterisks says trumpet- ar se. The second set is named after our old friend Reginald Swipe; R. Swipe for short!

panther3485

Vike
02-09-2006, 04:29 AM
Originally posted by Low_Flyer_MkVb:
Source: The Guns of the Royal Air Force 1939 €" 1945. G.F. Wallace
William Kimber. London. 1972.
ISBN 7183 0362 8

[BS and so on...]

<span class="ev_code_YELLOW">Luftwaffe Major Werner Molders (11-july-1940):</span> "North of Dover we met some low-lying Spitfires. I shot [one] down in flames. But now I found myself in the middle of a clump of Englishmen and they were very angry with me. They all rushed at me, and that was my good luck. As they all tried to earn cheap laurels at the expense of one German, they got in each other's way. Well, I managed to outmaneuver them and made them even more confused. Nevertheless, I couldn't avoid being hit. Bullets bespattered my aircraft. The radiator and fuel tank were shot up badly and I had to make a getaway as quickly as possible. Luckily my engine held out to the French coast, then it began to misfire. When I wanted to land the [landing gear] wouldn't work. There was nothing to do but land without it. I made a smooth belly landing."

<span class="ev_code_YELLOW">Luftwaffe Hauptmann Hannes Trautloft:</span> "A fantastic fireworks. Shots ring to my right and left. Somewhere in my Messerschmitt I feel a strong blow and hear a heavy rumbling, but the opponent has to go! I see a thin line of smoke under his fuselage, then suddenly the enemy plane is one red ball of fire rushing downward."

Without any doubt,the early109 20mm canons weren't good guns,be sure! http://forums.ubi.com/groupee_common/emoticons/icon_rolleyes.gif http://forums.ubi.com/groupee_common/emoticons/icon_biggrin.gif

OMG,it's a real Zoo here.... http://forums.ubi.com/groupee_common/emoticons/icon_eek.gif http://forums.ubi.com/images/smilies/16x16_smiley-indifferent.gif

@+

StG2_Schlachter
02-09-2006, 04:33 AM
Hey Karaya!

Both your clips show Hurricanes! Where is the Spitfire? http://forums.ubi.com/images/smilies/16x16_smiley-indifferent.gif

Maybe effectiveness is also based upon the trajectory of the bullets. In a turning fight, the MG/FF was very hard to aim with. The videos show planes being bounced from behind. No sign of evasive action.

But damage wise, the 20mm was clearly superior to the Hurricane and early Spitfire.

Strange, normally british literature on WW2 is kind of neutral.

Kocur_
02-09-2006, 04:35 AM
Originally posted by Low_Flyer_MkVb:
Source: The Guns of the Royal Air Force 1939 €" 1945. G.F. Wallace
William Kimber. London. 1972.
ISBN 7183 0362 8

G.F. Wallace was senior technical officer of the Gun Section of the Directorate of Armament Development.

(Chapter 16: The German Guns.)

€œOur only interest in the German guns was to keep a check on them to see that they did not outclass our own guns; this they never did.€

The Oerlikon 20mm gun.

€œThis was one of the Germans€ big mistakes. It was produced by the Oerlikon Company as an aircraft gun, a smaller, lighter, but supposedly equally effective version of their heavy ground anti-aircraft 20mm gun. The Oerlikon was a pure blowback gun which meant that for a high-powered cartridge the breech block had to be very heavy or to be attached to something very heavy. The anti-aircraft Oerlikon used a cartridge of similar power to the Hispano 20mm. To lighten the gun for aircraft use, Oerlikon reduced the powder charge considerably. This meant that the length of the cartridge was greatly reduced, which in itself meant a shorter gun, and the reduced power of the cartridge meant a much lighter breech block assembly. The length of the barrel was also reduced. All this meant that the muzzle velocity was greatly reduced, but this was considered acceptable for two reasons. Firstly, the gun would only be used at very short range in air fighting, and secondly, as the 20mm shell depended for its€ effect on its€ explosive charge, the velocity on hitting the target was unimportant. The first premise was true enough, but the second proved a complete fallacy €" as was soon proved in the Battle of Britain. Owing to its€ low velocity, the short Oerlikon gun had no greater penetration than the rifle calibre bullet, possibly less.€

€œIn general, the short Oerlikon was no more effective than the rifle calibre gun, so the Me. 109 with its€ two 7.9mm guns and two 20mm short Oerlikon guns was completely outgunned by the Spitfire and Hurricane. Had the Me. 109 been fitted with two guns firing the full-powered anti-aircraft Oerlikon cartridge, the story would have been very different.€


The guy doesnt sount SO objective... Neither well informed...

There was no anything like "Oerlikon reduced the powder charge considerably" to create FF. Oerlikon FF, i.e. basis for German Ikaria MG FF, was the first of Oerlikon's 20mms, based directly on WW1 Becker gun and its ammo 20 x 70RB. Oerlikon's version had a bit larger ammo 20 x 72RB. The LATER Oerlikon 20mms had more powerful cartridges, and were known as FFL (20 x 101) and FFS (20 x 110). In fact amunition for MG FF was 20 x 80mm, i.e. was larger than original 20 x 72mm Oerlikon's ammo for FF. Hispano ammunition is based on 20 x 110mm Oerlikon FFS, i.e. Oerlikon gun and ammo developed a good while AFTER FF.

Those Oerlikon guns were not "a pure blowback gun". Thety were API blowback or advanced primer ignition blowback. In pure blowback, popular in lower energy pistols and smgs, the primer is ignited when bolt and cartridge are in the full forward position. So to secure that case doest retract from chamber more than thickness of its base, the bolt must be as heavy as, simplifying things: weight of projectile x lenght of barrel / thickness of case base. In case of API blowback the primer is ignited just before bolt and cartridge reach full forward position. So bolt can be lighter, since part of blowback energy is consumed for stopping still forward moving bolt.

Claim that "the short Oerlikon was no more effective than the rifle calibre gun" is nothing but grotesque. Penetration of 20mm MG FF projectiles may have been lesser than mg vs armoured plate, but we are talking here about soft target, i.e. planes airframe. Efectiveness of MG FF, not to mention MG FFM, i.e. FF modified to fire Minengeschoss, was incomparable to any mg with any ammo. Firstly due to blast, secondly due to fragments.

To sum up: close this book and never open it again... BoB fighter armament of both sides is so different and so difficult to asses which was better considering respectful targets, that there is no need to misguide readers in order to demonstrate, that 8 x .303 Hurricane and Spitfire outgunned Bf-109E3/4/7.

Vike
02-09-2006, 04:38 AM
Originally posted by Kocur_:
The guy doesnt sount SO objective... Neither well informed...

It the least we can say! http://forums.ubi.com/groupee_common/emoticons/icon_eek.gif http://forums.ubi.com/groupee_common/emoticons/icon_biggrin.gif

@+

F0_Dark_P
02-09-2006, 04:39 AM
TROLL!!!
http://img.photobucket.com/albums/v238/Nahoj/troll.jpg

Kocur_
02-09-2006, 04:39 AM
Originally posted by Vike:
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by Kocur_:
The guy doesnt sount SO objective... Neither well informed...

It the least we can say! http://forums.ubi.com/groupee_common/emoticons/icon_eek.gif http://forums.ubi.com/groupee_common/emoticons/icon_biggrin.gif

@+ </div></BLOCKQUOTE>

Indeed http://forums.ubi.com/groupee_common/emoticons/icon_biggrin.gif

JG52Karaya-X
02-09-2006, 04:40 AM
Originally posted by StG2_Schlachter:
Hey Karaya!

Both your clips show Hurricanes! Where is the Spitfire? http://forums.ubi.com/images/smilies/16x16_smiley-indifferent.gif

My fault - got them from Google video a long time ago and kept their original names.

StG2_Schlachter
02-09-2006, 04:42 AM
You have to love Kocur_

Good posting http://forums.ubi.com/images/smilies/25.gif

Kocur_
02-09-2006, 04:45 AM
Originally posted by StG2_Schlachter:

Both your clips show Hurricanes! Where is the Spitfire? http://forums.ubi.com/images/smilies/16x16_smiley-indifferent.gif


In fact I'd say that "Hurricane" is a Defiant!

Oh, ty btw, I just have some good books http://forums.ubi.com/groupee_common/emoticons/icon_cool.gif

StG2_Schlachter
02-09-2006, 04:49 AM
If you pause the video and look closely at the canopy, i think you are right.

Xiolablu3
02-09-2006, 05:14 AM
The British knew that the .303 were inferior to the Germans 20mm even as the battle was going on, but they didnt have reliable 20mm cannon at that time. Its always better to have smaller guns that work than bigger ones that dont.

You can see the low muzzle velocity of the cannons on those clips Schlachter posted, which is a disadvantage. But if they hit, they were devastating. You see how close the German planes are in those clips, they look to be under 100 feet.

20mm Oerlikon, much better, there is no doubt, but as a German pilot put it in an interview I saw :-

'The British planes had so many bullets spraying about they were bound to hit something important.'

As the Battle of Britain went on the Germans added more and more armour plate to their planes and the British were finding it was taking more and more bullets to get the German planes down. This is when they decided to miss out 50 cal and go straight onto Hispano 20mm.

In the Battle of Britain the British guns favoured the beginner/novice, the Germans favoured the Marksman.

I am afraid I disagree with the original quote.

JG52Karaya-X
02-09-2006, 05:19 AM
Originally posted by Xiolablu3:
You can see the low muzzle velocity of the cannons on those clips Schlachter posted,

Didn't know that I'm a split personality http://forums.ubi.com/groupee_common/emoticons/icon_biggrin.gif

Aaron_GT
02-09-2006, 05:36 AM
This is when they decided to miss out 50 cal and go straight onto Hispano 20mm.

That decision had already been taken in around 1937, hence a series of specifications which called for 4 cannon fighters, with versions of the Hurricane and Spitfire with 4 cannon being tendered.

Blutarski2004
02-09-2006, 05:48 AM
There WAS a problem with German 20mm during the period of the BoB, but it had to do with the ammunition and not the gun. The fusing of the 20mm HE round was discovered to be far too sensitive, detonating the round at the very first touch, before it penetrated into the airframe. The fuze was so sensitive that a strike on plexiglass of a cockpit canopy would initiate it. Much of the effect of the round was wasted in the surrounding open air. As a result, the Germans found their 20mm guns under-performing in terms of lethality. After the BoB, a fuzing change was instituted which solved the problem.

Mr Wallace's exact words were:

QUOTE -
Owing to its€ low velocity, the short Oerlikon gun had no greater penetration than the rifle calibre bullet, possibly less.
-UNQUOTE

Mr Wallace may have been wrong in identifying the cause of the problem as low muzzle velocity, and his claim that the overall performance of the 20mm was no better than that of a 303 MG is certainly debatable, but the man was broadly correct in his description of the relatively poor penetration displayed by the 20mm MGFF HE round during that period of time.

vanjast
02-09-2006, 06:13 AM
I do remember a comparison between BoB planes some time ago. The spits and hurri's had a lot more guns, so the brits thought these outgunned the germans, they got a suprise when a proper comparison between guns was done.

It was found that although the germans had fewer guns, the amount of 'lead' slung around far outweighed the brits, as well as the destructive power of the german cannons. The .303 brownings were found to be ineffective, and the Brit pilots have confirmed this.

You have to validify your stats before you blab...
http://forums.ubi.com/images/smilies/10.gif

allmenroder
02-09-2006, 08:48 AM
Of more interest to me is thinking about what is going on in the cockpit of one of the Hurris that is hit.

A typical relexive action of a right handed pilot pulling the stick aft and maybe a little left; I'm guessing as a reflex to a hit in the pilot's torso.

whiteladder
02-09-2006, 08:57 AM
It was found that although the germans had fewer guns, the amount of 'lead' slung around far outweighed the brits, as well as the destructive power of the german cannons. The .303 brownings were found to be ineffective, and the Brit pilots have confirmed this.

IIRC the British moved away from the .303 not because it was ineffective compare to German fighter armament, but the difficulty they found in destroying German bombers.

JG53Frankyboy
02-09-2006, 09:00 AM
well, it looks like that the RAF had the armament for the Luftwaffe's main task: shooting down fighters

and the Luftwaffe had the armament for the RAF's main task: shooting down bombers

http://forums.ubi.com/groupee_common/emoticons/icon_smile.gif

tigertalon
02-09-2006, 09:35 AM
I would sheet my pants if any (MG, HE or APIT) FF shell was tossed to me barehanded.

DmdSeeker
02-09-2006, 10:21 AM
""so the Me. 109 with its€ two 7.9mm guns and two 20mm short Oerlikon guns was completely outgunned by the Spitfire and Hurricane."

Sorry but that's just BS.

I wonder how the Bf109E could shoot Spitfires and Hurricanes into flames then - must have been those über-Mg17s then"

Impressive film clips; but to be honest not much more than I would expect from a Spitfire's; or even more so a Hurri's guns at a similar range; admitidly it's have to be at or near convergence to do so (convergence being in my eyes a major advantage of the 109's).

After all; he's not saying the LW was underarmed; but that in his view the RAF's was better.

Given the job each side had to do; it's always struck me that each side was armed for the other's task.
The RAF had masses of little, fast bullets to bring down buffs; whilst the LW had slow firing cannons to bring down one of the war's most twisty fighters.

Xiolablu3
02-09-2006, 10:26 AM
Originally posted by JG52Karaya-X:
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by Xiolablu3:
You can see the low muzzle velocity of the cannons on those clips Schlachter posted,

Didn't know that I'm a split personality http://forums.ubi.com/groupee_common/emoticons/icon_biggrin.gif </div></BLOCKQUOTE>

Ooops sorry, those videos Karaya posted. , sorry...

Abbuzze
02-09-2006, 10:57 AM
Done by something similar to a 0.303 calibre

http://forums.ubi.com/groupee_common/emoticons/icon_biggrin.gif

http://mitglied.lycos.de/p123/bilder/MGFFwDelay.jpg

LUFT11_Hoflich
02-09-2006, 11:44 AM
Hmmm... GE Fighters undergunned?? Sounds like Horse Sheet to me...

4 .303 hits... make 4 nice little holes that could hmmm go in-out though soft places.

1 20mm hit... makes hmm what.. a 7" hole? not counting like you guys said.. structural damage and fragmentations.

To me is like being shot from 3 meters with a 3 burst 9mm gun vs a Shotgun. same thing... 3 small nice holes.. vs... patient ready for open heart surgery http://forums.ubi.com/groupee_common/emoticons/icon_eek.gif

Just my 2 cents here
H¶f...

Ruy Horta
02-09-2006, 01:59 PM
I have that book, really nice read, especially if you are interested in RAF technology. The author's bias must be seen against his background, and should be forgiven.

horseback
02-09-2006, 02:47 PM
The issue for the author (and the RAF) seems to be that it is better to get lots of hits with BBs than a very few with shotgun slugs (but when that slug hits...OMG!).

The problem was that in the early stages of the war, the Brits' fighters were shooting at elephants and the German's fighters were shooting at sparrows.

The .303s hitting at convergence would tear the hell out of most aluminum skinning (the RL consequences of which are underappreciated in this game), and could make aircrew very uncomfortable if they hit anywhere near the cockpit or crew spaces, but they did little in the way of structural or catastrophic engine damage. Fuel tanks could be another matter, however.

The wing mounted cannon of the Emil fired more slowly, had less chance of a hit for an average pilot, and provided a good bit less firing time for the weight of ammo.

From the British point of view, even if it had been available, the 2 x 20mm MG/FF would have been less suitable for them than the 8 x .303.

cheers

horseback