Ideal WW2 fighter gun armament

[ra]

WWI fighter designers did not have the option of mounting MGs in the wings because MGs needed to be in reach of the pilot.

ra

[Nefarious]

"That's why the British were so keen on the 20mm..." Tony Williams

Actually....

"Basic Arnament, remained as eight wing housed .303 Browning MGs for the vast majority of Spitfires in the battle, but at least one heavier armed version saw brief combat then. This was the Mark Ib, armed with two 20mm Hispano Cannons, and 19 Squadron was re-equipped with Mark Ib's at the end of June, flew "service trials", then took thier cannon armed fighters into action in August. By the end of the same month, however the squadron had become frustrated by constant feed stoppages and jams in the ammunition supply, and were reallotted a batch of 8-gun Mark Is to continue combat."

excerpt from Supermarine Spitfire by Chaz Boyer.

[GRUNHERZ]

I read they had the 20mm for appx a day then immediatly went back to 8 .303 because they didnt work.

Anyway .303/.30/7.7/7.92 all became worthless as fighter weapons through WW2, no matter how many were mounted.  Remember the typhoon was supposed to have some 12 .303 but the 4 20mm were found to be better.

[Tony Williams]

The 20mm Hispano had major teething problems; partly to do with the gun itself, partly to do with the mountings.  In the first Spitfire mountings the guns were mounted sideways to bury as much as possible of that bulky drum magazine within the wing, and boy, did the gun not like it  

Incidentally, the 20mm also had problems in US service for various technical reasons associated with its manufacture.  It wasn't considered satisfactory by the USN until well after the war.  I've not heard any criticism by the USAAF of the P-38 installation, though; has anybody?

Tony Williams
Author: Rapid Fire - The Development of Automatic Cannon, Heavy Machine Guns and their Ammunition for Armies, Navies and Air Forces.
Details on my military gun and ammunition website: http://www.users.globalnet.co.uk/~autogun/

[F4UDOA]

Tony,

The Navies problems with the 20Mill where found in the F4U-1C above 20,000FT with gun jamming because of cold tempatures. Once heaters where brought in and retro-fitted the problems disappeared hence the Navy standardizing on the 20mil by 1946.

In the mean time the F4U-1C flew low CAP at Okinawa. The AF really lagged in this department even mounting 50cal in the F-86 in Korea.

[Naudet]

That answer is very simply, 3x MG213/20 in a position either like in the LA7 (inline with the fusalage) or like the 3xMG151 in the FW190D13 (one through spinner 2 in wing roots).

When i remember right, ROF 1200 per gun and veloctiy of more than 3000ft/sec. and also nearly as much explosive as the MK108.

Or for buff hunting 3x-4x MG213/30 nearly same ROF and velocity but even more explosive carried in the shell.

[Tac]

Tony, the P-38 pilots would usually have to cock and hit the cannon many times if it was not maintained properly or if the aircraft had fired the gun under high-g's.

But I still say, I would MUCH rather have a .303 gatling on the nose of my 38 with 5000+ ammo on it than the 4 .50's and 1 20mm cannon. The ROF of that puppy plus the ammo load plus the cheapness to produce the ammo and the single gun plus cheapness of maintainance/production of a gatling plus giving a lot of ammo wouldve been HEAVENLY. I can see the 109's and He111's being cut by that can opener.

Imo, German pilots loved their cannon, but most of them said the US planes had better chances because they could fire a LOT of .50 at them.. and in many cases, the dogfights would require some spraying to get hits. German planes could not afford to fire like that, the US could. The brits and their .303 planes were deadly at mid-close ranges..which was where most of the kills during the war took place anyway.

Maybe HT will one day model fantasy loadouts.. I can only dream  

[DB603]

S!

 I would stay with 1-2 cannons and a few MG's.Cannons have very limited ammo load and MG's deliver quite punch in groups and can have significantly more ammo.And the guns have to be German made  

[Tony Williams]

A combined response, Gentlemen:

Tac - thanks for the word on the P-38's gun.  I can't agree about the .303 calibre, though.  I have reports of British wartime tests of .303 and 7.92mm AP ammo against a Blenheim fuselage (hardly the toughest of aircraft).  These revealed that most of the bullets fired never even made it to the armour plate; they were stopped by the light-alloy structure.  The RAF would have been better off if the .303 had been replaced by a good HMG (or better still a cannon) before WW2 began.  Anyway, specifying a gatling is cheating; they didn't enter aircraft service until long after WW2!

Naudet - specifying a revolver cannon like the MG 213C is cheating as well; they required massive development and didn't enter service until the mid-1950s.  Incidentally, the MK 213/30 version had a low muzzle velocity of around 530 m/s, IIRC.  And I'm not sure how they would take to being synchronised; it would certainly slow them down a lot.

F4UDOA - the problems with the US version of the 20mm were more serious than just gun freezing.  Chinn has a lot to say about poor manufacturing tolerances (they were classified as artillery so built to the same standards as battleship guns...) and the wrong chamber length, which were not corrected until after the war.  I have a blow-by-blow account of this somewhere (possibly on my Delphi site).

DB 603 - have to disagree with you about the German guns.  The best gun designers, by a mile, were the Soviets (the Russians still are), probably followed by the Japanese.  If you look at the specs for my "ideal" 20mm and 30mm, the closest actual match were the 20mm Ho-5 and the 30mm Ho-155, both Japanese.  The problem was the poor-quality materials mean they had to de-rate them.

Tony Williams
Author: "Rapid Fire: The development of automatic cannon, heavy machine guns and their ammunition for armies, navies and air forces"
Details on my military gun and ammunition website: http://www.users.globalnet.co.uk/~autogun/index.htm

[Naudet]

Originally posted by Tony Williams:

Naudet - specifying a revolver cannon like the MG 213C is cheating as well; they required massive development and didn't enter service until the mid-1950s.  Incidentally, the MK 213/30 version had a low muzzle velocity of around 530 m/s, IIRC.  And I'm not sure how they would take to being synchronised; it would certainly slow them down a lot.

I agree that synch would slow em down and that 30mm has low velocity (sry made mistake while remembering, high velocity 30mm were the MK101 and MK103) but from the source i have the info about the MG213 ("Deutsch Luftrüstung 1933-1945" from Heinz J. Nowarra) i have the following data:

MG213/20
lenth: 1930 mm
weight: 75 kg
ROF: 1300
velocity: 1065 m/s
bullet weight: 115 g


also there were atleast 10 guns build in the period of 1942-1945, and mass production was planned for 1945.


So lets say, that i am not cheating, i just would build the latest weapons evolution of WW2 into my bird  


If u would only want mass WW2 weapons, i would like u either take the HO-105 20mm or the late Sowjet 20mm.

There is no doubt that japan and russia build the best guns in WW2 in mass production.

[ 07-11-2001: Message edited by: Naudet ]

[Nefarious]

I have to disagree about the quality of Japanese Guns.

I dont know to much about Japanese Aircraft Guns. But I do know that Japanese Infantry weapons (especially MG) were at best horrible. Again I am not an expert but from what ive seen and read about Japanese Infantry weapons were very unreliable. Maybe you should enlighten us Tony on the types of Japanese Aircraft Guns and manufacturers! I sure do want to know.

[Tony Williams]

Nefarious, it is necessary to distinguish between quality of design and quality of manufacture.  I entirely agree that the quality of manufacture of Japanese guns fell away badly towards the end of the war, because they were increasingly limited to poor-quality materials and manufacturing methods.

An examination of the designs showed what they could have produced, if it were not for the above problems.  The Ho-5 was a scaled-up Browning .50, chambered for a 20x94 cartridge which had the case capacity to be considerably more powerful than the MG 151/20 (if only they hadn't had to down-load it to avoid breaking the poor-quality guns).  The Ho-5 was also both faster-firing and lighter than the MG 151.

The Japanese Army also scaled-up the Browning to 30mm (Ho-155) and 37mm (Ho-204) again producing light, compact and fast-firing guns chambered for potentially powerful cartridges.

The Japanese Navy was less adventurous, but they did manage to improve the Oerlikon guns by making them belt-fed (the Germans and Swiss both failed at this) and ultimately increasing the rate of fire to 670-750 rpm (the Germans and Swiss never got their aircraft guns much above 500 rpm)

There were also the Kawamura designs such as the 30mm Type 5 gun, another light, powerful weapon.

The Japanese were not as good as the Russians at coming up with original designs, but they were excellent at taking an existing design concept and improving it to levels which the western nations seemed unable to match - some things haven't changed!

Tony Williams
Author: Rapid Fire - The Development of Automatic Cannon, Heavy Machine Guns and their Ammunition for Armies, Navies and Air Forces.
Details on my military gun and ammunition website: http://www.users.globalnet.co.uk/~autogun/

[Tac]

Heh, gimme 5000rnds of .303 and ill take over ze world!  

My knowledge on guns and weapons is limited, personally I hate them in RL. Like them online though   . That's why I said that the .303 cartridges fired by that gatling would have a long casing for more punch and if I may add... would be nice for them to have mixed AP AP/I AP/HE tips. *drool*

[CJ]

If they were in existance, i always figured about a 17mm  high velocity multi barrel cannon synched to fire through the prop hub would be perfect for a ww2 fighter.  I guess around 5000-6000 rpm would open up anything in a half second burst, and with about 800 rounds it would be about right.  Just a scaled down vulcan.  It seems you'd need something about halfway between a .50 cal and a 20mm in round mass to do the job, but still have a decent ammo load.  Everything would be centered, ballistics would be great, and roll moment would be minimized.  Not sure how far along the development of gatling guns could have been taken back then, but i'd imagine it could have been done.

CJ

[Tony Williams]

Originally posted by CJ:
If they were in existance, i always figured about a 17mm  high velocity multi barrel cannon synched to fire through the prop hub would be perfect for a ww2 fighter.  CJ

Do you mean synchronised to fire through the propeller disk or mounted to fire (unsynchronised) through the hollow propeller hub?  If the former, you'd be wasting your time because the synchronisation would cripple the rate of fire.  If the latter, a multi-barrel rotary is too bulky to fit between the banks of an aircraft engine.  The only layout which would have permitted this was the P-39's, which moved the engine out of the nose.

Curiously, there was a prototype British fighter of the early 1930s (IIRC) which had the same layout as the P-39 with the pilot sitting on top of the propeller shaft (it was a biplane, though) and it was suggested at the time that a motorised gatling-type weapon firing through the propeller hub might be a good idea, but nothing came of it.

Tony Williams
Author: "Rapid Fire: The development of automatic cannon, heavy machine guns and their ammunition for armies, navies and air forces"
Details on my military gun and ammunition website: http://www.users.globalnet.co.uk/~autogun/index.htm