Ad: This forum contains affiliate links to products on Amazon and eBay. More information in Terms and rules
I doubt that anyone is saying that the 303 penetrated armour as well as the 0.5 but it is true to say that when the British tested the 0.5 against the Me 109 from behind the 0.5 didn't penetrate the armour on the pilots seat. I suspect the two facts became confused. No one would disagree that the 0.5 would and did do a lot more damage to the target aircraft than a 303. Engines, fuel tanks and all the other vulnerable parts were far more vulnerable which is why from late 1944 the 4 x 303 were normally replaced by 2 x 0.5.."The Air Ministry rejected the idea of using 2 x .5" with 2 x 20mm, at first, because they discovered that, from directly behind, a .5" bullet was no better at penetrating German armour than a .303","
I have learned more from this website in a month about WW2 airplanes than I did in my previous 30 years of studying WW2. Ballistics, on the other hand, make me shake my head. How could anyone that isn't drunk or smoking crack, possibly believe that a 180 grain .311 caliber bullet at 2500 feet per second could penetrate as well as a 650 to 800 grain bullet moving between 2800 and 3000 feet per second? Have you guys that are arguing for the .303 ever held one in your hand next to a .50 Browning?
When the RAF decided to make the change to the 20mm the 0.5 M2 wasn't around, the M1 was part of the test and therefore the M2 wasn't an option. On that basis the stopgap choice of 8 x LMG whilst the 20mm was sorted out was a good one when you remember that in 1935 when the decision was made, no aircraft had armour or self sealing tanks. What the RAF were guilty of was not sorting out the 20mm earlier.The simple fact is, the British made a terrible mistake choosing the .303 over the .5 Browning. It was a stopgap weapon and a poor one at that.
The .303 wasn't even a good cartridge compared to the 30-06 or the 7.92, being at least 200 feet per second slower. Ballistically, it barely beats out the old 30-30. The simple fact is, the British made a terrible mistake choosing the .303 over the .5 Browning. It was a stopgap weapon and a poor one at that.
That is cold comfort to Allied airmen that were shot down by the Japanese army and navy pilots whose 7.7mgs were actually .303s
Memo dated 12th January 1944, from the Director of Operational Requirements to the Chief of the Air Staff, headed ".5 Gun Secondary Armament in Spitfire" states 8th June 1942 "Letter from C-in-C. fighter Command asking that "Universal" wing of Spitfire V, VIII and IX be deleted and that armament be standardised on 2 x 20 + 4 x .5, or if this were not possible, 2 x 20 + 2 x .5. This change was required as performance was adversely affected with 4 x 20mm and the alternative 2 x 20mm + 4 x .303 was not considered adequate."Don't know where the info came about the Air Ministry "discovering" that the 50 BMG would not penetrate any more armor than the 303 but that sounds a little iffy to me. The US fighters armed with 50s seemed to do fairly well against the armor in German AC. At 500 yards the AP bullet in the 50 BMG will penetrate .75 inches of face hardened armor. Double post, I apologise.
The Ki 27 Nate used a pair of 7.7s, the Ki 43 used either a pair of 7.7s or one 7.7 and one 12.7 for the early part of the war, the Zero carried 60 rpg for it's 20mm guns for the first 6 months of the war if not longer. All IJA victories in the early part of the war were achieved without 20mm guns.
The .303 actually has an almost identical muzzle energy to a 7.62x51 NATO round, while this is a small step down from the 30-06 and the German 7.9mm it isn't quite down to a .30-30 either.
The weight of 4 50cal guns is about 30kg more than the weight of the guns ( two 7.7mm+ two 20mm) in the Zero and the weight of a useful amount of ammo would have added even more to the weight difference.
The M2 was a good gun but not great and it was not a good choice for planes with limited amounts of power. The gun itself was heavy for it's power and the ammo, while possessing good kinetic energy, was also heavy.
More than one early war US fighter may have suffered in combat due to being overloaded with guns and ammo for the power available.
Early Zeros had under 1000hp and the 66lb weight difference is just for the weight of the guns. the Zero carried 1000rounds of 7.7mm ammo which equals about 200 rounds of .50 cal ammo. The Japanese 20mm ammo used a cartridge case that was 27mm shorter than a .50 cal case and only 1.6mm fatter. While the projectile was much heavier the complete round didn't keep the same proportion. An empty .50 cal case weighs more than the bullet it fires. you are lucky if you would get much more double the number of the number of .50 cal rounds than the 20mm. Even throwing in the weight of the drums on the cannon is still going to mean adding even more weight than the 66lbs to get to even 200 rounds per gun for four .50s. You could be looking at 90-120lbs more weight with even a modest amount of ammo (200rpg). Wildcats with 4 guns carried 400rpg which would add 240lbs more than 200rpg.
Combat persistence is part of the problem. The Zero ran out of 20mm ammo in about 7-8 seconds but had about 33 seconds of ammo for it's 7.7mm. A four gun Wildcat had about 32-33 seconds of firing time, cutting the ammo to 200 rpg cuts the firing time to 15 seconds. Hurricanes and Spitfires had 15-17 seconds of firing time for their .303s.
If the Russians truly pulled the wing .30s from the early P-40s they must have been really desperate. The rate of fire for the synchronized .50s was really pathetic, some times down to 450rpm. Two of them would give you 900-1000rpm total, makes the 9600rpm of a .303 armed Spitfire look really good.
The US navy eventually agreed with you about the F4F-4. Later versions did drop back to 4 guns but they did it to increase the ammo carried from 1440 rounds for six guns to 1720 for four guns. Apparently they didn't like the shorter available firing time even with the extra fire power per second.
what was the average time of a dogfight? 1 on 1? I think the answer is there, thats were the superiority of the 50cal or
13mm rounds come into play. now vs a bomber like a landcaster or B-17's 8 x .303's firing for a minute is utterly useless,
50cal/13mm is quite a bit better. 20/30mm shells will do the job.
20/30mm shells vs a fighter, well it dosn't matter how many are fired and it dosn't matter at what rate, 1 or 2 hits will
get the message across.
as far as removing the outer 50cals, some P-40's did that in N.Africa. result: increase climb rate, slight increase in acceleration.
the practice was abandoned though, as the extra 50's were needed against the Bf109F/G's.
conclusion: 2x13mm w/ cannon fuse mount was great for head on and rear attacks. 8 x 303 or 6 x 50cals great for deflection shooting.
as far as removing the outer 50cals, some P-40's did that in N.Africa. result: increase climb rate, slight increase in acceleration.
the practice was abandoned though, as the extra 50's were needed against the Bf109F/G's
If the 2 popguns firing through the prop wont bring an enemy aircraft down, it doesn't matter how much ammo you have for them.
F4F4's carried 240 rounds per gun. I believe some P40's carried about the same amount. I would rather have 200 to 250 rounds for a 50 than 1000 for the Red Ryders up on the engine cowling.
Bad analogy's, you don't "spray" an elephant (or even spray the area it is in which is what some air combat came down to) with gunfire and hope to hit a vital part. your tank analogy might be better if compared a Sherman with a 75 to a Sherman with a 17pdr. and even then it depends on the target.Same if I was elephant or buffalo hunting, I would rather have 10 rounds of 375 H&H than 100 of 223. Sherman tanks with a 75mm carried twice the number of rounds as a Tiger with an 88mm, which would you rather have?
According to Robert Johnson, a Fockwolfe sat behind him and hosed his P47 with LMG fire until he ran out of ammo. According to Saburo Sakai, he did the same thing to a Wildcat until he finally switched back on his cannon and finished it off.
I would argue that in either case, particularly the Wildcat, 50's would have finished the job without cannon, especially at point blank range like both of these examples were.
what was the average time of a dogfight? 1 on 1? I think the answer is there, thats were the superiority of the 50cal or
13mm rounds come into play. now vs a bomber like a landcaster or B-17's 8 x .303's firing for a minute is utterly useless,
50cal/13mm is quite a bit better. 20/30mm shells will do the job.
20/30mm shells vs a fighter, well it dosn't matter how many are fired and it dosn't matter at what rate, 1 or 2 hits will
get the message across.
what was the average time of a dogfight? 1 on 1? I think the answer is there, thats were the superiority of the 50cal or
13mm rounds come into play. now vs a bomber like a landcaster or B-17's 8 x .303's firing for a minute is utterly useless,
50cal/13mm is quite a bit better. 20/30mm shells will do the job.
20/30mm shells vs a fighter, well it dosn't matter how many are fired and it dosn't matter at what rate, 1 or 2 hits will
get the message across.
as far as removing the outer 50cals, some P-40's did that in N.Africa. result: increase climb rate, slight increase in acceleration.
the practice was abandoned though, as the extra 50's were needed against the Bf109F/G's.
conclusion: 2x13mm w/ cannon fuse mount was great for head on and rear attacks. 8 x 303 or 6 x 50cals great for deflection shooting.