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luftluuver
02-20-2008, 10:00 AM
At the Joint Fighter Conference in October 1944, Commander Monroe of the USN Ordnance branch reported the following:

Commander Munroe said the following:

"I wonder if somebody in the Army could explain why the Army is not interested in the 20mm gun. They developed it but apparently have no requirements for it while the Navy feels quite differently about the gun. We are going to it in a large way, I trust, in that we are putting it in the Fleet to let them try it out. I personally have a tremendous amount of confidence in the gun and believe the requirements will be very great. Anybody in the Army who can speak on that?"

Colonel Coats from Eglin Field responded:

"I'll try to answer that in this way. I believe the feeling in the Army generally is that we would like to have a lethal density pattern. The most bullets going across one place at a given instance. We would like to have the smallest caliber gun that can do the job. If it takes a 22mm to tear a Messerschmitt or a Mitsubishi apart, we want 20's, but as long as a 50 will do the job we feel that if we can carry a greater number of guns and a greater amount of ammunition with the same weight, with an equal or greater firepower, that is the gun we want. If you are strafing an airdrome you can put out more bullets. A Jap doesn't care whether he gets killed by 20 mm's or a 50 caliber. We can put out more bullets and we have more weight covering the same area. Another thing that comes into this matter of sighting is the training of the personnel. When wew get sights to the point where we can pull the trigger just once and hit a fellow, then we can go to the bigger calibers. It is a matter of training of pilots. The Mark 14, the gyro sight, we found didn't increse our accuracy for our control gunner to any great extent. However, it did bring the people in the middle and lower brackets up as much as 5 or 6 times better than they had shot before. I think we in the aircraft game should be worrying about the people in the middle third or the bottom half, that we have to make better sights, better cockpit arrangements, easier planes to fly for those people. We don't need to worry about our top shot or our best pilot. he can get along in any kind of a rig. That is the reason- we feel we can get a bigger density pattern.

"I would also like to point out, I won't go into an argument with 20's versus 50's, but I thik a lot of it has to do with the arrangements in the plane. For instance, in a P-47 or F4U, you have all the guns in the wings. Of necessity you must cross the fire pattern at some fixed distance from the plane. With all your guns over one fixed point at a given number of yards, you have a great X forming out there. At 600 you are wasting a great amount of your bullets. If you close up on a fellow to 200 yards, you are also wasting bullets. In the F7F or the P-38 you can put all your guns in the nose; firing parallel streams of lead, your bullets all going out forming a lethal density pattern as far as the bullets go. In an installation like that you could possibly be better off firing four 20's than you would be firing six 50's. In the P-47 with four guns in each wing, we recommend that they cross the first two guns at 250 yards, the next at 350, at 450 and 550. That gives you a density pattern in depth as well as width for about 200 yards, which in turn gives the mediocre pilot a better opportunity to hit an airplane in flight."

K_Freddie
02-20-2008, 11:12 AM
10 pages for sure http://forums.ubi.com/groupee_common/emoticons/icon_wink.gif

For the army: 50 cal gun is lighter to carry/handle

For der air force:

I'd say with a lot of 50 cals flying around they bound to hit something sensitive which might increase your advantage. If all is in focus then they pack a punch.

Cannons pack a punch focussed or not.
http://forums.ubi.com/groupee_common/emoticons/icon_cool.gif

Tater-SW-
02-20-2008, 11:24 AM
Well, I think the beaten zone argument is certainly in line with AAF doctrine regarding ground attack. In the case of the 5th AF, for example, the purpose of the guns on the bombers was not just to kill/destroy, it was to suppress.

PhantomKira
02-20-2008, 11:25 AM
As K_Freddie points out, lighter (50 cal) rounds require more hits to do damage. With a 20mm cannon, you might just get a single hit, but when it hits, it hurts. I think it's a toss up in principle. It depends on the mission really.

I do prefer cannons to MGs though, simply because I know a hit means serious damage... I just have to be more careful with the trigger and make sure I have a good sight picture before I fire. Of course, this philosophy assumes a single mindedness towards air combat.

One13
02-20-2008, 11:30 AM
Here is a link that might help-cannon or machinegun? (http://www.quarry.nildram.co.uk/CannonMGs.htm)

HayateAce
02-20-2008, 11:53 AM
P47s with 6x20mms would have been too cruel to use on a battered luft.



http://forums.ubi.com/images/smilies/crackwhip.gif

Viper2005_
02-20-2008, 12:03 PM
IIRC the USN placed more emphasis upon gunnery than the USAAF prior to WWII.

This was perhaps because the USAAF's primary emphasis was upon bombers rather than fighters (witness the Norden bombsight, and the turbo-supercharged high altitude bombers designed to carry it).

It must be remembered that the defensive problems associated with attempting to protect cities from aerial bombardment were effectively insurmountable even with RADAR; although heavy losses could be inflicted, the bombers could and did get through if those responsible for sending them were prepared to accept such losses.

.50 " HMGs are a good defensive armament for bombers because they allow you to put lots of rounds in the air. Flexible guns as fitted to bombers are inherently less accurate than fixed guns fitted to fighters, so a "spray and pray" weapon makes sense in that context. If you've got to have a lot of HMGs for your bombers, it makes good logistical sense to put them in your fighters too. Since the USAAF was part of the US Army, and the US Army needed HMGs for General Purpose use, this argument was further strengthened.

Meanwhile, the USN had somewhat simpler defensive problems (since ships are much harder targets to hit than cities), and considerably greater motivation to solve them!

Additionally, even large aircraft carriers could not handle genuine heavy bombers, so heavy bombers could not compete with fighters for resources.

And since naval aircraft historically proved unable to compete with their land-based counterparts in terms of pure performance (due to the increased mass fraction of their landing gear, more severe structural requirements and so on), it made considerable sense for the USN to grab the most advanced armament available in an attempt to level the playing field.

Finally, the stores required to operate naval aircraft must be carried within the aircraft carrier, and since ships are inherently expensive, it follows that a great deal of money may be saved if smaller, lighter stores may be used.

Cannon shells are bigger and heavier than HMG rounds, but they have a higher energy density, and therefore promise to be more effective per unit mass or volume provided that you can hit the target with them. Since aircraft will generally use fewer shells per sortie than they would use HMG rounds, the supply problems are reduced (albeit in exchange for a greater risk of explosion aboard ship; but carriers are dangerous places anyway...).

As such, it is unsurprising that the USN and USAAF/USAF should have come to rather different conclusions about the optimal armament for their aircraft.

flakwagen
02-20-2008, 12:03 PM
I've long assumed that 'fifties' were used for the reasons mentioned. Shotguns generally make better home defense weapons than pistols for the same reason. They give the poor to average marksman a fair chance of landing a hit.

Flakwagen

Kocur_
02-20-2008, 12:06 PM
Colonel Coats from Eglin Field responded:
(...)

Good colonel forgot to mention among that BS he said, that his Army, after like four years just quietly stopped producing their 20 mm cannons, which were put in the very, very back of the warehouses right after leaving factory, and most of the tens of thousands of guns produced were just being scrapped, for the idiotic errors made by said Army in the course of production made those weapon useless. I wonder if he knew, that things he was saying were silly excuses or perhaps he belived the fairytales that US Army had to make up to cover the US Hispano scandal.

One13
02-20-2008, 12:18 PM
Here is that story-US hispano cannon (http://www.quarry.nildram.co.uk/US404.htm)

BOA_Allmenroder
02-20-2008, 12:34 PM
I think the issue of 'beaten zone' is lost on most who have never fired machine guns before.

Basically, with machine guns, you're coverging beaten zones at a give range (well really same with cannons).

You can bolt a machine gun down in 10 ft of cement, bore sight it, and squeeze the trigger for 2 or 3 sections and you'll see your rounds impacting in and around you boresighted target.

Thats why when you see WW2 video of machine guns hitting a plane or the ground, or a box car, you see what looks like an envelope to bullets hitting the target.

I don't know if this game simulates that or not, it doesn't feel like it does but the game is what it is.

Tater-SW-
02-20-2008, 12:54 PM
I saw Letters from Iwo on TV the other night, and the strafing F4Us made perfect little lines of bullet impacts, LOL. riiight.

The fact of the matter is that regardless of what BuAer said they didn't actually switch from 0.50 cals during the war with limited exceptions (night fighters, etc). The reason was that the 0.50s were demonstrably "good enough," and the pilots (in the navy anyway) consistently favored firing time over other constraints.

The principal complaint about the F4F-4 (aside from it being much more of a pig than the -3) was that the 6 gun armament had only about 1/2 the firing time"”which is why they went with 4 guns for the FM-2 (and the F8F, for that matter).

The USAF made a similar choice witht he F-86, though I'm not sure why since the shot pattern with nose mounted guns would not be an issue.

tater

Jaws2002
02-20-2008, 01:12 PM
In US it was a combination of many factors.

-Rigidity of mass production. A new gun was not desperately needed so they kept what they had in production.
-When they decided to build a cannon the model they chosed was not the best representant of the type. While the Hispano II had awesome balistics and good hitting power, was heavy, still drum fed, with very limited ammo capacity, had low rate of fire and was still unreliable for a wing instalation. On top of that, during the translation of the bluprints they messed up some measurements and did some changes that made the gun even more unreliable.
The true is that the fifties were ok in fighting what they had to fight most of the time: small single engine fighters. But that doesn't mean a set of GOOD RELIABLE 20mm cannons wouldn't have done their job easier. The navy quickly introduced 20mm when they had to do the killing quick (Carrier deffense against kamikaze). Here it was very important to get them as fast as possible. every extra second you spend on the tail of one of them means that another one has a chnce to make it in.

I'm absolutely certain that if USA had to fight bombers more often, or if they had a chance to build a better gun from the begining (MG151/20, B-20, Hispano V) they would have built it and it would have replaced the fifties during the war.

Tater-SW-
02-20-2008, 01:26 PM
Very true.

BTW, this is OT a little, but it is a problem you frequently see in ww2 "what if" type games. WW2OL is a great example. While the number of planes is limited right now, as they progress into heavy bombers, as a matter of balance they will provide them for both sides. The players can then chose to develope the heavies, but since the allies didn't have to face them in any numbers in RL, they will have no purpose built counters (or even purpose altered variants). Any "online war" type campaign will suffer from this if limited to only RL operational aircraft since the axis tried a little of everything, and the allies built what they needed.

Blutarski2004
02-20-2008, 02:02 PM
Question - Was the 20mm Oerlikon ever evaluated for use in aircraft? If not, why not? The US churned out countless thousands of these reliable and effective weapons during the war for use by the USN.

Aaron_GT
02-20-2008, 02:23 PM
Cannon shells are bigger and heavier than HMG rounds, but they have a higher energy density, and therefore promise to be more effective per unit mass or volume provided that you can hit the target with them.

Presumably, though, this argument would hold for aircraft too - fewer but larger and more destructive rounds could mean an overall reduction in mass.

With regard to the P-47, if fitted with 4 20mm cannon it would be able to carry a lot of ammunition, and if the USN 3:1 figure is to be taken then it would have a higher firepower.

In terms of chances of hitting, that's asymptotic. After you have a few guns adding more doesn't increase the chances of hitting much (assuming you are on target) but rather increases the number of hits. It's like rolling dice. Roll 4 and your chance of getting at least one six is (1-chance of no sixes) of (1-5*5*5*5/6*6*6*6) or about 50%. With 8 it is about 75%. With 12 (e.g. Hurricane IIb) it would be 90% . So increasing the number of guns by 100% increases the chance of hitting by only 50% (50 + 50% of 50 is 75%) over what you had before, or 25% in absolute terms. Approximating with dice is a bit artificial of course - in reality the chances of hitting are not so independent, but that actually favours increased number of guns less.

On the other hand moving from 2 to 4 trials makes a lot of difference - 0.16 to 0.48 in one jump.

The optimum depends on factoring in weight, and real chances to hit. Dice are easy to understand than the 1/6 chance is not -so- far from typical hit rates, and on a large sample set that's about equal to the chance of each hit (if independent trials, which they aren't in reality).

Jaws2002
02-20-2008, 02:28 PM
Originally posted by Blutarski2004:
Question - Was the 20mm Oerlikon ever evaluated for use in aircraft? If not, why not? The US churned out countless thousands of these reliable and effective weapons during the war for use by the USN.



Again Anthony G Williams has the answer: http://forums.ubi.com/images/smilies/11.gif http://forums.ubi.com/images/smilies/11.gif

http://www.quarry.nildram.co.uk/apib.html


"As described in "Rapid Fire", the first API Blowback cannon was the 20mm Becker which saw German service, as both an aircraft and an AA gun, at the end of the First World War. SEMAG bought the design and produced a more powerful version firing a longer cartridge (the Type L). Oerlikon then took over and introduced the Type S, firing an even bigger cartridge. By the late 1920s, the range consisted of guns built around three different 20mm cartridges; in order of increasing size and power, the Type F (70mm case length, later increased to 72mm), the Type L (99mm, later 100mm or 101mm in the Japanese Type 99-2) and the Type S (110mm). Their muzzle velocities were respectively around 600 m/s, 750 m/s and 820 m/s. These three ranges continued to be developed together.

In the mid-1930s, all three guns were offered in improved versions, suitable for aircraft use. They were known as the FFF (usually just FF), FFL and FFS respectively. Hispano Suiza produced modified versions of the FFS as the HS Type 7 and Type 9, modified for aircraft engine mounting. The Japanese acquired and experimented with the FFS as an aircraft gun but never used it in service. The British Royal Navy acquired the FFS as an AA gun, but in a heavier and sturdier version known as the Type SS. It saw extensive service throughout the Second World War (being used by the Army as well) and remained in naval use into the 1980s. The USN also used this model. Oerlikon continued to improve the SS range until after the Second World War, the last being the 2SS, capable of firing at 650 rpm. Polish engineers working in Britain produced a much simplified version of the SS known as the Polsten, which saw some service late in the War."

The type of Oerlikon used and licence built by the US was the heavier SS version wich was more suitable for AA gun.

Aaron_GT
02-20-2008, 06:01 PM
and the F8F, for that matter

A criticism of the F8F in the JFC was lack of firepower likely being an issue.

Aaron_GT
02-20-2008, 06:04 PM
When they decided to build a cannon the model they chosed was not the best representant of the type. While the Hispano II had awesome balistics and good hitting power, was heavy, still drum fed, with very limited ammo capacity, had low rate of fire and was still unreliable for a wing instalation.

These problems were fixed and the Hispano II had a successful life in British aircraft, though. In terms of ROF it was 600 rpm, which is less than the M2 or MG151, but hardly earth shatteringly slow like a 37mm cannon.


I'm absolutely certain that if USA had to fight bombers more often, or if they had a chance to build a better gun from the begining

The odd thing, though, is that it was presumed that the USA would need to be defending various territories against bombers, hence the P-39, and the various heavy cannon installations in the P-38 early on. It seems that they didn't find the right cannon at the right time, and the whole thing was deprioritised.

The UK saw 4 (or 6 in twins for bomber destroying, like the Supermarine 323) 20mm cannon as the way to go from the mid 1930s with designs for 4 cannon Spitfires and Hurricanes appearing in around 1937. 4 cannon was pretty much the minimum standard RAF fighter armament by late 1941, apart from in the Spitfire. It seems to have worked well enough against fighters.

I suspect the big issue was that the US version of the Hispano wasn't reliable when the decisions on armament were being made, and by the time it was it wasn't worth changing production over, although the P-51 had proved it could easily take 4 20mm cannon, but it might not have had enough firing time with 4 for escort, and 2 would be too few. A Spitfire IXe armament might have worked well, but logistics would have made using just 50 cals all round easier. The RAF has to contend with three different calibres. Part of the reason why the Spitfire went to a 1 cannon/2 .303 wing was due to having lots of 303 guns and ammunition production capacity and stocks, and not enough 50 cal to go to 1 cannon/1 .50 wings.

What would have made more sense for BoB, absent 20mm cannon, would have been Hurricanes and Spitfires armed with 2 .50s per wing, like the Belgian (or is it Dutch) Hurricanes. That would have been a stronger armament that 8 303s.

Tater-SW-
02-20-2008, 07:18 PM
Originally posted by Aaron_GT:
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">and the F8F, for that matter

A criticism of the F8F in the JFC was lack of firepower likely being an issue. </div></BLOCKQUOTE>

None the less, they built it with 4x.50.

The firing time issue was huge, though. F4F-3/FM-2 with nearly 40 seconds of ammo vs 19 seconds in the -4. That's why F4F-4 drivers turned off the outboard 2 guns and saved them.

tater

Kocur_
02-21-2008, 03:34 AM
Originally posted by Tater-SW-:
The fact of the matter is that regardless of what BuAer said they didn't actually switch from 0.50 cals during the war with limited exceptions (night fighters, etc). The reason was that the 0.50s were demonstrably "good enough,"

No. The problem was unreliability of 20 mm M2 cannon, thanks of US Army production program of that weapon. I know it's hard to belive, but between 1940 and 1944 US Army contractors produced exactly 134.663 (one hunderd and thirty four thousand, six hundred and sixty three) examples of AN M1 and AN M2 20 mm cannons and vast majority of them went from factory straight to storage and scrapyard, because they just wouldn't work!
Even when examples of 20 mm M2 coincidentally meeting specs were found in lots delivered for USN, they still needed oiled ammo... In short: US Hispano wasn't reliable enough for anyone to risk full implementation where guns were the primary weapon, ie. in fighters. That's why the first USN plane armed with them was Helldiver. If cannons failed in a dive bomber it was't a big deal, as long as it could drop bombs. US Navy finally could do, what they wanted to do for years that is swich to cannons, since at least 1939 only after they had their own cannon production program and results were satisfactory enough.


Originally posted by Tater-SW-:
and the pilots (in the navy anyway) consistently favored firing time over other constraints.

Yes, when it came to options of four and six .50s and early war Japanese planes. They never had a chance to compare any number of 50s. with whatever ammo count vs. US Hispano - well, not until night F6F-5 and very few F4U-1C. And afterwards 200 rds per 20 mm cannon of those years never was exceeded.


Originally posted by Jaws2002:
In US it was a combination of many factors.

-Rigidity of mass production. A new gun was not desperately needed so they kept what they had in production.

It was needed desperately enough for US Army to order 44.747 US Hispanos until early 1941 (and thousands were delivered in 1941). If that's not desperate need, I dont know what is.


Originally posted by Jaws2002:
-When they decided to build a cannon the model they chosed was not the best representant of the type. While the Hispano II had awesome balistics and good hitting power, was heavy, still drum fed, with very limited ammo capacity, had low rate of fire and was still unreliable for a wing instalation.


US bought their cannon directly from French (well they actually stole it earlier, not being able to wait for finalizing of the deal, by reverse engineering of test examples delivered in 1938), it was not some derivative of British Hispano. And should have been... For as early January 1942 the British delivered drawings of BH Mk.II, which was cured of earlier teething problems and was produced in UK succesfully until was replaced by Mk.V.
US adopted Chatellerauld belt feed about the time British did, so low ammo count was not an issue since 1942.


Originally posted by Jaws2002:
On top of that, during the translation of the bluprints they messed up some measurements and did some changes that made the gun even more unreliable.

Well, the problem was that by US Army bureaucracy the 20 mm *automatic* cannon was just another artillery piece, due to exceeding .60 '' caliber IIRC, so the production program was managed by US artillery. So they used their artillery quality standards and NOT small arms quality standards. In artillery say 0.02 mm was just nothing, while in case of automatic weapon headspace it made huge difference - like between good weapon and junk. And so from US Army paperwork point of view all US Hispanos were just top quality, while in reality they were just screwed up beyound human-knowledgable-in-small-arms understanding.
On top of that HS.404 really did benefit from shortening chamber, which was tried and used by British, but US Army ordnance engineers in their stupid pride "knew better" and just wouldn't listen to Limeys.


Originally posted by Jaws2002:
I'm absolutely certain that if USA had to fight bombers more often, or if they had a chance to build a better gun from the begining (MG151/20, B-20, Hispano V) they would have built it and it would have replaced the fifties during the war.

He, he. The funny part is that actually they tried reverse engineering of MG151/20, with results similar to those of reverse engineering of MG 42 (the US T44 machine gun)...

Aaron_GT
02-21-2008, 04:16 AM
None the less, they built it with 4x.50

It was a case of continuing with the tooling for the initial version, but the navy wasn't happy and the version was quickly replaced with a cannon armed ones as the navy felt even before it entered service that the armament was insufficient.

M_Gunz
02-21-2008, 07:16 AM
I keep hearing this idea that neglects a simple principle of power that the decision makers
were just helpless in the face of ordinance incompetence. That's utter rubbish. When those
guys want results, bad examples do not keep being made. Prototypes are checked and production
is checked. There surely was nothing approaching desperation in that program, not even strong
interest. It just doesn't happen when there is. Go look up war profiteering instead.

Kocur_
02-21-2008, 08:19 AM
Originally posted by M_Gunz:
I keep hearing this idea that neglects a simple principle of power that the decision makers
were just helpless in the face of ordinance incompetence. That's utter rubbish. When those
guys want results, bad examples do not keep being made.

You dont seem to comprehend. Those "examples" were fine.
On paper.
Then they were stopped being made... in early 1944.


Originally posted by M_Gunz:
There surely was nothing approaching desperation in that program, not even strong
interest.

Yeah, ordering nearly FIFTY THOUSAND of aerial guns by spring 1941 (and there were further orders, mind you!), that is enough to install three of them (planes like P-40 and F2A were to carry two, P-51 had four, P-38 and P-39 had one as we know) in EVERY fighter produced in US in 1941 AND 1942 is just "not even strong interest", right http://forums.ubi.com/images/smilies/16x16_smiley-very-happy.gif http://forums.ubi.com/images/smilies/touche.gif

Tater-SW-
02-21-2008, 09:04 AM
How many 0.50 cals were built? 500,000? 1,000,000? More? How many were ordered?

Just to get a perspective on the relative importance of the 2 weapons systems in terms of production.

Kocur_
02-21-2008, 10:11 AM
Originally posted by Tater-SW-:
How many 0.50 cals were built? 500,000? 1,000,000? More? How many were ordered?

I dont know, you tell me. But obviously you dont know that either, particularly for 1940/41...
But don't tell me that US Army, or rather USAAC(F) were not VERY eager to introduce 20 mm cannon and were decided to make this weapon primary fighter gun of 1940s. They just messed that up and next best thing was - luckily - .50 M2. US Army created all that mythology of .50 AFTER they screwed 20mm cannon program and the 20 mm vs. .50 "controversy" is just result of that flop. There would be none if those 130.000 US 20 mm cannons (there would be far more, the production ceased before US industry reached top level of production, not to mention that after 1942 nobody trated the weapon seriously) were useful and not junk.

Tater-SW-
02-21-2008, 11:29 AM
What was BuAer/BuOrds POV? The navy didn't switch, either.

No US fighters were designed and saw combat after the entry of the US into war (cept maybe the P-63, not sure when they speced it out, but it first flew dec 7, 1942, so it was likely in design stages more than a year previous. I don't count the Bearcat, either). If the prewar spec didn't have 20mm, then adding them, while desirable, wasn't really part of the long term plan. BuAer's spec for the F6F didn't have cannon, for example. So the notion that it was their intent from 1940 on is not true, IMO. It was on the table as a possible upgrade, clearly.

I think in the case of the PTO, there was no reason to change over, frankly. Only late, when you had to not just "mission kill," but actually disintegrate the enemy (kamikazes) did it become a critical issue in the PTO.

I'm not arguing that 20mm would not likely have been more effective, or even that the 20mm actually produced were not ****, resulting in an inability to test them in widespread use. I am saying that the doctrine as of December 7th, 1941 revolved (for the USN, certainly) around deflection shooting, and putting a lot of rounds downrange, guns harmonized at 1000 feet (sometimes slightly shorter based on squadrons, but that was rare) and none of the BuAer contracts as of that date specified 20mm cannon. This isn't just production, but also X versions. The XF6F-4 was the XF6F-1 aircraft with 20mm added. It was tested in October, 1942. That was the first test of 20mm in a USN fighter. So while the Navy might have wanted to transition to 20mm (assuming a decent gun was available), it was not part of a grand pre-war scheme or BuAer would have contracted to test existing aircraft like the F4F with 20mm.

I guess my argument is the choice of the word "desperate." We were "desperate" to beat the axis to a nuclear bomb, so we spent more than some countries' GDPs to build a few. We wanted 20mm, but produced an inferior gun that never got used. Perhaps the contractor gave FDR a big contribution, who knows. Building a hundred thousand guns would have been desperation for Japan, but for the US it was run of the mill porkbarrel spending.


tater

M_Gunz
02-21-2008, 12:31 PM
Originally posted by Kocur_:
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by Tater-SW-:
How many 0.50 cals were built? 500,000? 1,000,000? More? How many were ordered?

I dont know, you tell me. </div></BLOCKQUOTE>

It hasn't stopped you from making your own story or backing someone else's.
We could produce atomic bombs but oooh, those tricky 20mm cannon we were DESPERATE to have!

Go look up War Profiteering and try to get some perspective, the US produced almost 3,000,000
MG's not counting SMG's and aircraft guns. You want to talk numbers, scale to that.

Then some time go find out what power the General Staff had and learn the name John Marshall.
If they felt strongly, things would have gone differently. As much or more money was wasted
in trying to pick up production of GLIDERS but same time the bad was tracked down and put a
stop to.

We had 10 million men in the service by end of war with _everything_ being made and you want
to act like those cannon were some huge deal. Put in perspective, the line was already
formed for such boondoggles.

Desperate -- I like that! Same word as used about German fighter production, esp 262's!
Small wonder it gets used here. US must have been desperate for something! Yes, End of War!

Aaron_GT
02-21-2008, 01:18 PM
I guess my argument is the choice of the word "desperate." We were "desperate" to beat the axis to a nuclear bomb, so we spent more than some countries' GDPs to build a few. We wanted 20mm, but produced an inferior gun that never got used. Perhaps the contractor gave FDR a big contribution, who knows. Building a hundred thousand guns would have been desperation for Japan, but for the US it was run of the mill porkbarrel spending.

I think it is that some projects work (and it is worth noting that the atomic bomb effort was US led, but multinational, and from this project the whole science of project control was also born) and some fail. That a big project could work does not mean that smaller ones also work. Things get messed up, forgotten about, forms filled in triplicate and then lost in the back of filing cabinets, and some projects fall by the wayside.

Also very often the more important thing is to have volume of production, even if the individual items are not the best. Quantity has a quality of its own. Thus Shermans weren't a match for the Panther individually, but the quantity of production of something reasonable made more sense than tinkering for another year producing something better. I think the 50 cal falls into the Sherman category - it could be produced in numbers, and when it was being produced in numbers then the priority for the 20mm cannon reduced. Work still carried on, as the M3 appeared in (from memory) 1945. Prior to 1942 the USAAC brass DID want a 20mm gun (or heavier), though, and had the luxury of tinkering right up until the end of 1941.

If the Hispano II had been produced to the British tolerances from mid 1941 it would have solved a lot of problems in terms of 20mm cannon production in the USA, and I can't see why US types could not have made use of them, as a number of types did, if in limited numbers produced. I can't see that fitting four to a P-47 would have been much of a problem, for example, given that they managed to shoehorn in 4 37mm cannon!

Back in the 1930s the USAAC also showed a fair degree of interest in the 23mm Madsen cannon. Denmark being invaded put paid to that.

Tater-SW-
02-21-2008, 02:24 PM
Well, the Manhattan District was mostly multinational to the extent we had expats who emigrated to the US, then worked on it. We wrote the checks, however, 100%, so sending a few bright guys over was certainly useful, but the buck stopped with the US taxpayer (the other combatants being almost bankrupt).

Xiolablu3
02-21-2008, 02:53 PM
Ahh come on guys, the Manhatten project was a group of guys from all over the world, not just the US of A.

Saying, 'We' had no trouble making the atomic bomb, but couldnt manage a 20mm cannon doesnt really fit.

The A bomb was the result of a lot of men from a lot of different countries. Hell, didnt Einstein even write to Roosevelt about the danger of such a weapon? Which is sure to have sped things up in the development cycle.

AKA_TAGERT
02-21-2008, 05:29 PM
Originally posted by luftluuver:
At the Joint Fighter Conference in October 1944, Commander Monroe of the USN Ordnance branch reported the following:

Commander Munroe said the following:

"I wonder if somebody in the Army could explain why the Army is not interested in the 20mm gun. They developed it but apparently have no requirements for it while the Navy feels quite differently about the gun. We are going to it in a large way, I trust, in that we are putting it in the Fleet to let them try it out. I personally have a tremendous amount of confidence in the gun and believe the requirements will be very great. Anybody in the Army who can speak on that?"

Colonel Coats from Eglin Field responded:

"I'll try to answer that in this way. I believe the feeling in the Army generally is that we would like to have a lethal density pattern. The most bullets going across one place at a given instance. We would like to have the smallest caliber gun that can do the job. If it takes a 22mm to tear a Messerschmitt or a Mitsubishi apart, we want 20's, but as long as a 50 will do the job we feel that if we can carry a greater number of guns and a greater amount of ammunition with the same weight, with an equal or greater firepower, that is the gun we want. If you are strafing an airdrome you can put out more bullets. A Jap doesn't care whether he gets killed by 20 mm's or a 50 caliber. We can put out more bullets and we have more weight covering the same area. Another thing that comes into this matter of sighting is the training of the personnel. When wew get sights to the point where we can pull the trigger just once and hit a fellow, then we can go to the bigger calibers. It is a matter of training of pilots. The Mark 14, the gyro sight, we found didn't increse our accuracy for our control gunner to any great extent. However, it did bring the people in the middle and lower brackets up as much as 5 or 6 times better than they had shot before. I think we in the aircraft game should be worrying about the people in the middle third or the bottom half, that we have to make better sights, better cockpit arrangements, easier planes to fly for those people. We don't need to worry about our top shot or our best pilot. he can get along in any kind of a rig. That is the reason- we feel we can get a bigger density pattern.

"I would also like to point out, I won't go into an argument with 20's versus 50's, but I thik a lot of it has to do with the arrangements in the plane. For instance, in a P-47 or F4U, you have all the guns in the wings. Of necessity you must cross the fire pattern at some fixed distance from the plane. With all your guns over one fixed point at a given number of yards, you have a great X forming out there. At 600 you are wasting a great amount of your bullets. If you close up on a fellow to 200 yards, you are also wasting bullets. In the F7F or the P-38 you can put all your guns in the nose; firing parallel streams of lead, your bullets all going out forming a lethal density pattern as far as the bullets go. In an installation like that you could possibly be better off firing four 20's than you would be firing six 50's. In the P-47 with four guns in each wing, we recommend that they cross the first two guns at 250 yards, the next at 350, at 450 and 550. That gives you a density pattern in depth as well as width for about 200 yards, which in turn gives the mediocre pilot a better opportunity to hit an airplane in flight."
That Colonel Coats from Eglin Field is SAVVY!

Tater-SW-
02-21-2008, 05:48 PM
Originally posted by Xiolablu3:
Ahh come on guys, the Manhatten project was a group of guys from all over the world, not just the US of A.

Saying, 'We' had no trouble making the atomic bomb, but couldnt manage a 20mm cannon doesnt really fit.

The A bomb was the result of a lot of men from a lot of different countries. Hell, didnt Einstein even write to Roosevelt about the danger of such a weapon? Which is sure to have sped things up in the development cycle.

Einstein was an immigrant to the US.

What, now the US doesn't even get credit for the A-bomb any more? It was a world, team effort? Um, no. People who left other countries (most never to return), yeah. Brits and Canadians who participated, yes as well. Americans work for Airbus and BMW, too, that doesn't make Airbus or BMW part American.

tater

PS--while Los Alamos is behind a ridge from here, I can actually see the place where Trinity was (though it's over 100 miles away).

AKA_TAGERT
02-21-2008, 05:52 PM
Originally posted by Tater-SW-:
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by Xiolablu3:
Ahh come on guys, the Manhatten project was a group of guys from all over the world, not just the US of A.

Saying, 'We' had no trouble making the atomic bomb, but couldnt manage a 20mm cannon doesnt really fit.

The A bomb was the result of a lot of men from a lot of different countries. Hell, didnt Einstein even write to Roosevelt about the danger of such a weapon? Which is sure to have sped things up in the development cycle.

Einstein was an immigrant to the US.

What, now the US doesn't even get credit for the A-bomb any more? It was a world, team effort? Um, no. People who left other countries (most never to return), yeah. Brits and Canadians who participated, yes as well. Americans work for Airbus and BMW, too, that doesn't make Airbus or BMW part American. </div></BLOCKQUOTE>
Agreed 100%


Originally posted by Tater-SW-:
PS--while Los Alamos is behind a ridge from here, I can actually see the place where Trinity was (though it's over 100 miles away).
Really?

Where you live?

cloudcroft or alamogordo?

VW-IceFire
02-21-2008, 06:02 PM
Originally posted by Tater-SW-:
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by Xiolablu3:
Ahh come on guys, the Manhatten project was a group of guys from all over the world, not just the US of A.

Saying, 'We' had no trouble making the atomic bomb, but couldnt manage a 20mm cannon doesnt really fit.

The A bomb was the result of a lot of men from a lot of different countries. Hell, didnt Einstein even write to Roosevelt about the danger of such a weapon? Which is sure to have sped things up in the development cycle.

Einstein was an immigrant to the US.

What, now the US doesn't even get credit for the A-bomb any more? It was a world, team effort? Um, no. People who left other countries (most never to return), yeah. Brits and Canadians who participated, yes as well. Americans work for Airbus and BMW, too, that doesn't make Airbus or BMW part American.

tater

PS--while Los Alamos is behind a ridge from here, I can actually see the place where Trinity was (though it's over 100 miles away). </div></BLOCKQUOTE>
Well it was a pretty serious multinational effort. Lots of the work was done in getting the right people out of the hands of the Nazi's and into Allied hands just before the hammer dropped. Apparently there was consideration to do some of the work in Canada but it made sense to locate everyone in one spot and the US was footing most of the bill and providing most of the manpower. Was an impressive achievement of science and a terrifying weapon of war but try not to forget that lots of people from all different nationalities were contributing the the effort.

Churchill and Roosevelt were both made aware of the weapon by a variety of scientific sources in the US and in Europe. A combination of British and American intelligence efforts also made a pretty big contribution in making sure that Nazi efforts to build an atomic bomb failed or were delayed as well.

Only one country had the resources to properly bring it all together, organize it, and make it happen in short order. Credit deserved where its due but best to be realistic about all of the sources and people involved from all over. Not many were proud either but allot felt it was better they than the Axis.

Read A Man Called Intrepid. Its about how British intelligence was setup during the war, the people involved in the US Canada and Britain (and elsewhere), the early days of the FBI, and most interestingly all of the efforts surrounding the Manhattan Project from the intelligence perspective. Its very interesting.

Tater-SW-
02-21-2008, 06:06 PM
Albuquerque, but up near the Tram. I can see past Socorro from my living room window http://forums.ubi.com/groupee_common/emoticons/icon_smile.gif

Actually, I just checked google eath, and it looks like I assumed it was on the alluvial fan of the southern most mountains I see, but in fact they curve in front, and from my POV the site is behind them a few miles. I'd have seen the mushroom cloud, but not the ground itself, mea culpa!

tater

Tater-SW-
02-21-2008, 06:13 PM
I wasn't talking about spooks, I was talking about building a bomb. I suppose if intelligence and multinational are on the page then who gets credit for Klaus Fuchs? http://forums.ubi.com/groupee_common/emoticons/icon_wink.gif

I've met a surprising number of original Los Alamos guys given my tender age of 42. I know a lot of folks at the Lab, so I've lucked out and met a bunch before they died (mostly less well known guys, though I did meet Teller). My old roommate's dad was there right after the war (a physicist), and a few folks I met at their house turned out to be original guys (didn't know at the time, they were just old guys eating dinner at my friend's parents' house, lol.)

tater

Choctaw111
02-21-2008, 06:21 PM
Let's get some 50 cal vs. 20mm gun cam footage in here http://forums.ubi.com/images/smilies/25.gif

Aaron_GT
02-22-2008, 04:19 AM
Tater, one difference between Mahattan and Airbus is that Mahattan was set up explicitly as a joint US-Britain-Canadian project (under the US Army) whereas Airbus is not set up as a joint US-European project. You could say the same about Boeing - lots of Europeans work at Boeing but I wouldn't consider it anything other than a US company.

The USA can be rightly proud of having successfully executed the project, and of having contributed a great many scientists to it, and other nations can be rightly proud of having contributed to it too, if in lesser numbers. But, importantly, not all the research whent on in the USA. A key component was the uranium enrichment process, which was developed by two (British naturalised) central European emigres in Oxford. So this is why I feel it is best considered a multinational effort as key research contributing to the project was still going on outside the USA. Whether you count the Oxford contribution as British of German/Hungarian or the contributions of the likes of Teller as American or Hungarian I don't know. Maybe as all of the above, or maybe more as contributions from the free world to the enslaved parts of the world at the time would be more apt.

One of the ongoing contributions of the Manhattan project is, as I noted before, is the birth of the science of project control, which became formalised in the 1950s under with CPM and PERT. The need to control such a large project meant that this area of research was stimulated and has been helping to deliver projects to time (well, mostly http://forums.ubi.com/groupee_common/emoticons/icon_smile.gif ) ever since.

Ratsack
02-22-2008, 04:22 AM
Originally posted by Aaron_GT:
....
One of the ongoing contributions of the Manhattan project is, as I noted before, is the birth of the science of project control, which became formalised in the 1950s under with CPM and PERT. The need to control such a large project meant that this area of research was stimulated and has been helping to deliver projects to time (well, mostly http://forums.ubi.com/groupee_common/emoticons/icon_smile.gif ) ever since.

Aaaaaarrrrrrrggggghghhhhhh!!!!!!!!!!

Ratsack

Aaron_GT
02-22-2008, 04:44 AM
Not a fan of project control methodologies I take it, Ratsack. It's not the most thrilling of subjects, granted... But build a bridge or an airport, and the Manhattan lessons are... ok I'll shut up now.

Kocur_
02-22-2008, 10:12 AM
Originally posted by M_Gunz:
It hasn't stopped you from making your own story or backing someone else's.
We could produce atomic bombs but oooh, those tricky 20mm cannon we were DESPERATE to have!

Well, it's your personal problem, if you can compare easily US Hispano program of 1939-41 and entire Manhattan Project...


Originally posted by M_Gunz:
Go look up War Profiteering and try to get some perspective, the US produced almost 3,000,000
MG's not counting SMG's and aircraft guns. You want to talk numbers, scale to that.


If you want to talk numbers of weapons, scale up your knowledge, at least to level which will not let you compare smallarms production including army (land forces) weapons and aerial automatic cannon production. If you want to compare things comparable - compare almost 50 thousand 20 mm cannons ordered until spring 1941 and orders for other aerial weapons of *that period*.

Aaron_GT
02-22-2008, 10:21 AM
What were the relative figures, Kocur?

Von_Rat
02-22-2008, 10:25 AM
the manhatten project was multinational, in that it was a joint us, uk, canadian project.

but thats were it ends.

just because teller and silzard were hungarian or fermi italian, doesnt mean you add hungary and italy to that list.

btw im not belittling their contribution. but they were not representing hungary or italy, far from it.

M_Gunz
02-22-2008, 10:56 AM
It's no use trying to explain to Kocur, the failure of those guns and yet they were still
produced must mean whatever he wants it to, obviously. It cannot mean else, for sure.

M_Gunz
02-22-2008, 11:00 AM
Originally posted by Von_Rat:
the manhatten project was multinational, in that it was a joint us, uk, canadian project.

but thats were it ends.

just because teller and silzard were hungarian or fermi italian, doesnt mean you add hungary and italy to that list.

btw im not belittling their contribution. but they were not representing hungary or italy, far from it.

How the fuel was purified, I'm pretty sure that did not get shared until later. I can find out.
I also doubt that was the only secret kept. I am sorry to say that US seems to have had a
habit of taking but not sharing at least with Commonwealth. Other times it was opposite.
You'd almost think that different people and groups were involved instead of a monoblock
"government".

Aaron_GT
02-22-2008, 11:36 AM
M_Gunz, I'd agree that not all projects run in the USA during WW2 were necessarily successful. That's not surprising, really, as things do go wrong. That's why Manhattan stands out - it was the biggest single, most complex project undertaken during WW2, or you could argue, ever, to that date, and possibly ever since. And it worked. It's an incredible achievement of project control and delivery. Probably the thing that comes closest is Apollo, and that benefited from things like PERT developed in the wake of Manhattan.

M_Gunz
02-22-2008, 06:28 PM
130,000 20mm pieces of junk made until 1944 was a drop in the bucket is what I'm saying.
Just how and why it happened has a fishy odor that had there been desperation for those
would not have gone unchecked. Things like that did happen, times and places, and were
put a stop to.
What stinks is that one group may have wanted the 20's while another did not. They should
not have been produced but there it is. Compare to dozens of Waco gliders made wrong at a
few factories at high cost each while many times those were made right and some cheaper,
brass with interest got the incompetents and cheats sorted out in months. Desperation DID
operate there in setting up contracts to develop, those gliders were needed.

10 million things to do gearing up for and then prosecuting a war, don't you know that some
hindsight johnnies will add one and one to get three later on.

Grey_Mouser67
02-22-2008, 08:38 PM
Curtis managed to make outdate, obsolete aircraft the entire war and while it was because of need early on, it was purely politics and backscratching later on so to say that a bunch of bad cannons were made because the US was desperate is a reach of monumental proportions.

Don't mistake game ballistics and DM's for real guns. The .50 was very effective, especially when matched up with an API round and I think it is as simple as that...more guns, more bullets lots of fire!

jarink
02-22-2008, 08:41 PM
Not the only case of a weapon copied by the US being junk.

The US Army also tried copying the MG-42 and converting it to .30-06 caliber. (the T24 machine gun). After about a year of working on the project, two guns were made and rapidly experienced failures in testing. The problem? One of the engineers made a small error in one of the dimensions when calculating the cartridge conversion.

Both of the guns are still at the Springfield Armory (http://www.rediscov.com/spring/VFPCGI.exe?IDCFile=/spring/DETAILS.IDC,SPECIFIC=340,DATABASE=objects,).

GH_Klingstroem
02-22-2008, 11:35 PM
Originally posted by flakwagen:
I've long assumed that 'fifties' were used for the reasons mentioned. Shotguns generally make better home defense weapons than pistols for the same reason. They give the poor to average marksman a fair chance of landing a hit.

Flakwagen

That is true! Unfortunately we have the "point convergence" in the game which means there is practiacally NO spread of the bullet pattern at all! This was used by a few aces squadrons and a few aces in WW2 because the were extremly good at aiming. The average marksman needed a bigger spread to hit his targets. I would assume that most of us are average marksmen but with the point conervergense we have its very very difficult to hit your target thus all the .50s crying we hear!

Compare the 1938 Hurricane and the p47. Both have eight MGS. The p47 has point convergence and the Hurricane has bigger spread. Almost evertime you fire with the hurricane you will hit your target, in turns, long distance, high G etc etc. I wotn cause much damage with the .303s but just the fact that its sooo much easier to hit with!

M_Gunz
02-23-2008, 07:22 AM
Kling, if you fire short of convergence, what do you get for a pattern? I set mine long.

AKA_TAGERT
02-23-2008, 07:57 AM
Hmmmmm

decision time..

Take the word of ubi forum members that 'FEEL' the .50s was the wrong way to go during WWII..

or

Take the word of Colonel Coats from Eglin Field..

Geeee..

This is a really hard choice to make..

NOT!

Tater-SW-
02-23-2008, 11:04 AM
Originally posted by Tater-SW-:
Albuquerque, but up near the Tram. I can see past Socorro from my living room window http://forums.ubi.com/groupee_common/emoticons/icon_smile.gif

Actually, I just checked google eath, and it looks like I assumed it was on the alluvial fan of the southern most mountains I see, but in fact they curve in front, and from my POV the site is behind them a few miles. I'd have seen the mushroom cloud, but not the ground itself, mea culpa!

Took a picture, still hasn't cleared since the snow dusting, but here ya go:
http://i121.photobucket.com/albums/o222/tatersw/view_south.jpg
Jornada del muerto is just behind that distant mountain range (sorta to the right of the range).


BTW, that tower (center just below distant mountain) is south of the airport and is maybe 15 miles away. It is actually this tower:
http://hea.cwru.edu/stacee/images/sandia_back_view_small.jpg

M_Gunz
02-23-2008, 02:21 PM
Hi Tater, what's your alt there? I spent a couple weeks up by Cimmaron back in 72 and at
that 8000+ feet you can see clear for miles and miles and miles. It was incredible.

Tater-SW-
02-23-2008, 02:24 PM
The center of Albuquerque is at 5000 ft, my house is at 6500'.

M_Gunz
02-23-2008, 03:22 PM
Oh. You must be 'Mr. Iron Blood' then! And very used to clear air!
I'm living at about 1200' now, we get "a bit" more haze, LOL!
Down at sea level viewing distances... about 2 miles ground to ground on an average clear day?

Tater-SW-
02-23-2008, 03:25 PM
^^ that pic is hazy http://forums.ubi.com/groupee_common/emoticons/icon_biggrin.gif

M_Gunz
02-23-2008, 06:24 PM
For where you are it is! On the coast even a clear day is not that clear.
You would get claustrophobic I guess. http://forums.ubi.com/images/smilies/16x16_smiley-tongue.gif

The last time I saw the Milky Way, I was at 6500 ft in our main Division maneuvers area.
I miss seeing the heavens so clear, it kinda puts a man in his place.

Tater-SW-
02-23-2008, 06:28 PM
We get a fair bit of light pollution, but I can still make out the Milky Way. Drive a 1/2 hour out of town and you can read by it though.

M_Gunz
02-23-2008, 07:57 PM
Tater, I'd LOVE to see pics of that!
I think it'd be a safe guess that the majority of the population has never seen it except pics.

Skoshi Tiger
02-23-2008, 09:52 PM
Originally posted by Grey_Mouser67:
Curtis managed to make outdate, obsolete aircraft the entire war and while it was because of need early on, it was purely politics and backscratching later on so to say that a bunch of bad cannons were made because the US was desperate is a reach of monumental proportions.

Don't mistake game ballistics and DM's for real guns. The .50 was very effective, especially when matched up with an API round and I think it is as simple as that...more guns, more bullets lots of fire!

Hey alot of those outdate, obsolete aircraft (P-40's for instance) were being sent to places like Australia, where they were very much appriciated and valued. During the later stages of the pacific war our Spitfire MkVIII's didn't have the range for most missions, And the P-40's were a great ground attack plane with fairly long legs!

Outdate and obsolete aircraft? Yes!
Best we had that could do the job? Yes!

What was the quote about the p40? "Damned by workds, flown to glory!"

M_Gunz
02-23-2008, 10:03 PM
P-40M was obsolete now?

VW-IceFire
02-23-2008, 10:14 PM
P-40 was pretty much obsolete its entire run...maybe before it saw combat it was roughly on par with what was available elsewhere in the world but everything surpassed it rather quickly and the P-40s performance never improved significantly enough to redress the balance.

BUT...the P-40 was in production in large numbers at the start of the war and it was good enough to compete against superior opposition. I think the choice between a fighter with inferior performance but some redeeming qualities versus no fighter at all was a simple one. Part of the P-40s charm is that its pilots turned it into an effective fighting machine when the deck was stacked against them by the numbers.

Friendly_flyer
02-24-2008, 02:07 AM
Originally posted by VW-IceFire:
Part of the P-40s charm is that its pilots turned it into an effective fighting machine when the deck was stacked against them by the numbers.

I guess you could say that the P-40 was the American Hurricane. It might not have been the best machine around, but it was there when it was needed.

M_Gunz
02-24-2008, 07:06 AM
I guess that any plane is not the best for the entire war must be obsolete the whole time.

Erik Schilling doesn't seem to agree - what's his problem? (http://yarchive.net/mil/p40.html)

Don't just read pieces of it, he does go into 1943 North Africa action as well as China 1941.
Wasn't there some kind of war on then?

He is very good at separating tactics from the machine and about altitudes.

Yeah it was outclassed by the improved P-38's, by the P-47's and P-51's but even then the
pilot made the difference as many rookies found out in friendly competitions with the former
AVG pilots. Pilot quality differences was the main reason that the Zero did so well in the
start of the PTO. Once the US pilots developed better tactics, or adopted them, and Fighter
Command was established to unshackle the fighters from being grossly misused then things did
change as to effectiveness of planes said to be losers. Just as Goering had tied the 109's
to bombers (1/3rd had to stay close and slow, 1/3rd higher and 1/3rd free hunters - Galland)
so the US and British had done such mistakes, early in Typhoon they did even worse. The P-51's
were likewise tied close to the bombers when they started escorting and took many losses.

But if it wasn't in the top rank at the end it was obsolete at the start.........
I hope that some of you can finish a book or hour long TV show and remember the start and middle.

Aaron_GT
02-25-2008, 05:21 AM
Take the word of Colonel Coats from Eglin Field.

Or take the obviously erroneous 'feelings' of the USN, RAF, etc that felt the 20mm cannon would be better?

It seems the development of the 20mm cannon was cocked up a bit (it took a bit of fixing up before the British were happy with it too) and by that time the ramp up of production meant that it made logistic sense to continue with the 50 cal. It seems that in the US forces opinion was divided.

If the M2 20mm cannon had been reliable from the outset things might have been different, but it's impossible to know.

As a side not the RAF had the choice to go to 50 calibre guns in the 1930s but wanted to go straight to 20mm guns for bost offensive and defensive armament, although the latter was not achieved as although 20mm defensive turrets were developed they were not perfected until late WW2, only making it onto the Lincoln (dual 20mm mid upper). Some of the projected quad 20mm turrets were compact, others enormous, such as the ones for the B.1/39 projects (two quad 20mm turrets).

The Luftwaffe developed some cannon turrets, but again I am not aware of things like the quad MG131/20 tail turret actually making it onto anything. The most I am aware of is a few 20mm turrets, but mostly singles. The Ju 290 had quite a few 20mm guns for defence, but given its speed and ceiling it needed them!

The USA developed some post war 20mm barbettes (same form factor as those on the B-29) but again I don't recall them being used as the move was generally towards removing defensive armament. The USSR seemed to persist longer with 20mm and 23mm remote control defensive turrets.

Xiolablu3
02-25-2008, 07:32 AM
I think that the point where turrets were no longer viable is when jets arrived and they moved too fast for the remote controlled turrets then on the bombers.

I'm sure I remember reading about Korea when the B29's turret computer could not compute for anything as fast as a Mig15.

Aaron_GT
02-25-2008, 08:08 AM
Yes, turret slew was not fast enough, and shooting at long range via radar guidance (when angular rates are lower) not accurate enough. And then finally the move was towards defence against bombers via SAMs, and air-to-air attack via AAMs, so no fighters within gun range anyway.