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I would say that the MG151/20 would have been a much better weapon in fighter-on-fighter confrontations. It packed a heavy punch, it was lighter than the Mk108 while being slightly longer, it had a better rate of fire and most importantly, it had a far better range (800m) than the Mk108.So would just a couple of regular 20mm cannons have been effective to begin with?
I would say that the MG151/20 would have been a much better weapon in fighter-on-fighter confrontations. It packed a heavy punch, it was lighter than the Mk108 while being slightly longer, it had a better rate of fire and most importantly, it had a far better range (800m) than the Mk108.
Even the He280 was designed for the MG151/20, and was armed with three in the nose.
Shortround6, what do you think would have been an effective weapon configuration for the Me 262. Do you think that the idea of a Gatling gun was limited to only paper in the Second World War?
Here is a scale comparison between the Mk103, Mk108 and the MG213. Note that the MG213's size falls between the 103 and the 108.So are you saying that any Gatling type gun would be useless to even start with? I am not disagreeing with your statement, I find it to be very plausible, I just need you to affirm that the Gatling gun would not be very useful as it would have promised.
MG151/20 cannon. 42.7kg. 750rpm. 805 m/s. 18.6 grams of HE filler in shell.
2cm Flak38. 57.5kg. 480rpm. 835 m/s. 22 grams of HE filler in shell.
85 m/s greater velocity plus projectile 1/3rd heaver results in considerably improved long range hit probability. This allows enemy bomber boxes to (hopefully) be engaged outside effective range of their defensive machineguns. 20mm x 138mm cartridge is considerably more powerful then typical aircraft 20mm cannon rounds. They will hurt even against heavy bombers.
Why not a belt fed 2cm Flak38 for heavy fighter use? Long range capability for use against bombers and lethal to enemy fighter aircraft. Weapon weight almost identical to low velocity 3cm Mk108 cannon.
You also have to remember Newton's 3rd law. If you fire heavier projectiles at higher velocity you get more recoil. Granted the heavier gun damps this down a bit but then Mr Benders information is off more than just a bit. The Flak 38 fired similar weight projectiles about 200 meters faster than the MG 151. They may have loaded down the high capacity Mine shell due to the thin walls, just a guess but why the mine shell would be fired about 65 ms a second slower than the thick wall shell I don't know.
You also have a problem with the belt feed, it will slow the gun down as it takes power to operate the feed. The Flak 38 was recoil operated. Please look at the Hispano which was a hybrid. gas unlocked it but there was also a recoil component. Hispanos with a muzzle brake almost always feed from the drum. They took the muzzle brake off to get enough power to operate the belt feed. Also please note that the Flak 38 used a cartridge case 56mm longer than the MG 151 which means, assuming the same length projectile (or same length sticking out the case mouth that the bolt has to travel 56mm more each way per round fired. even at 450rpm that is an extra 50+ meters of bolt travel per minute over a MG 151 firing at 450rpm.
The Hispano used a 110mm case.
I am also truly amazed that the Flak 38 with about 47,000 joules of muzzle energy (119gram projectile at 900m/s) is such a devastating weapon firing at 450-280rpm cycle rate (not including magazine changes) and yet the Hispano with 50,300 Joules (128-130gram projectile at 880ms) and firing at 600rpm is almost considered an also ran.
You want a good alternative armament for the Me 262? Stick four belt fed Hispanos in the nose. Perhaps not as dangerous to bombers but you aren't going to get much better for fighter vs fighter in late 1944.
Here is a scale comparison between the Mk103, Mk108 and the MG213. Note that the MG213's size falls between the 103 and the 108.
View attachment 292591
However, we're back to the 30mm versus the 20mm question. The 20mm round is certainly effective against enemy fighters and in the fighter role, the Me262 could well have used the 20mm to good effect. A battery of four MG151/20 would have had range, hitting power, adequate ammunition stores to make it a potent contender.
It's true that a 30mm minengeschoss round would tear the wing off of a P-51, but that is complete overkill, considering the 20mm would do considerable damage in it's own right.
To give you an idea of how much room is really available in the nose of the Me262, here is a diagram of the Me262A-1a/U1 and how the MK103, Mk108 and MG151/20 were fitted. Note the limited area for ammunition storage that's packed around the nose-gear bay. Also, the MG151/20 barrels and the Mk103 barrels were protruding, which caused a noticeable buffeting effect while in flight. If the MG151/20 were placed where the Mk103 is shown (C) and the Mk108 is shown (A), then the barrels would be embedded, thus avoiding the buffeting. There would also be more storage area for the ammunition - the increased weight of the ammunition and the lighter weight of the MG151/20 falling within the historical design load of the MK108 ammunition.
View attachment 292590
I think you are working on a pipe dream. There is nothing the luftwaffe could have done short of coming up with a science fiction death ray and a plane that could be flown by not very bright and rather clumsy 14-15 year olds that would have stopped the American bombers in 1944. North American was building about 700 Mustangs a month. They were building about 500-600 P-47s a month and 3-400 P-38s, granted some were going to the Pacific but the chances of the Americans running out of fighters was pretty slim (throw in the British fighters and there was no chance).
People have been arguing for decades (and will argue for decades more) if the P-51 was the equal of certain models of the Fw 190 ( and few will push the 109K) but the main problem was that on average the American (and allied) pilots of 1944 were better than the German pilots of 1944. The Germans had their 'experten" but they were running out of them and the replacement pilots just didn't have enough training for more than a very few to survive their first combat missions. Sticking them in jets wasn't going to change things enough. The Germans weren't going to be able to play a war of attrition with the allied fighters and shoot down so many that the Americans would run out of fighters and send over bombers unescorted. They would simple wait a few weeks until another few hundred fighters were delivered.
The Germans only chance was to bypass the fighters and try to kill enough bombers (4 engines and 10 men are harder to replace than one engine and one man) so the Americans would stop/pause and rethink the bombing campaign.
The four 30mm cannon in the 262 was about as good as it was going to get for killing bombers. With average pilots getting about 2% hits of rounds fired the 262 carried enough ammo for 1-2 kills on 4 engine bombers. if you needed 15-20 20mm hits and only got 2% hits you need 720-1000 rounds of 20mm ammo per kill and NO daylight fighter was going to carry that ammo load and be able to stay on target long enough (multiple passes?) to fire it all anyway. These are averages from experten to green pilots. You can't build fighters set up for experten when you are running out of them.
I want to see what could have been possible. I understand that Germany's lack of better pilots was a factor in losing the air supremacy the Luftwaffe had in Europe. I am saying that if the Me 262 had been introduced around late 1942, there being experienced pilots in that time, with production of piston planes halting, shifting toward jet production, then a significant difference might have embroiled.
I only ask for the most plausible possibilities, and also what do you think could have helped the Germans win the air war?