It still amazes me the value the US had in the 50cal, but I guess that was real and this is a game.
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It was, still is, and always will be one of the greatest military cartridges of all times and it was plenty adequate for WWII aerial combat. However, that doesn't mean it was the most effective weapon available. I see arguments about weapons come up a lot that go something like "if this other weapon was better, then why wasn't it used instead or sooner?" It's not that simple. Weapons weren't chosen simply based on how destructive they were, there are many other factors involved. The War Dept. came under heavy criticism at the end of WWII over their reluctance to put into service a heavy tank until it was too late to make much difference. That's an interesting story in itself but it just goes to show that that argument doesn't hold up. There are bureaucracies involved and differing opinions on the matters.
In terms of power, the .30-06 is greater than the .308 which is greater than the .223. Yet our small arms have gone away from the heavier cartridges and for good reason.
Back to the subject of the .50. Here was a fine weapon which had been in production since 1921. But even before WWII started, the need for heavier armament was seen. A request for a 20mm weapon was issued in 1936 after some tests were conducted at Aberdeen. Unfortunately, through the 30s, hardly any money was available to ordnance research and this didn't appreciably pick up until 1939 when it more than quadrupled over the previous year as the clouds of war started to loom in a big way. In 1937 work was begun on the design of a domestically produced .90 caliber(about 23mm) weapon. This project was canceled as it became apparent that it would take too long and attention was turned towards weapons of foreign design. The same month that the .90 cal project was started, a promising report describing the Hispano-Suiza 404 came in and one was ordered for testing. While waiting for the new weapon to come in, tests were performed at Aberdeen on a 23mm Madsen, 20mm Rheinmetall, 20mm Oerlikon, and an earlier version of a 20mm Hispano. After extensive tests, the Hispano 404 won out and in 1939, more examples were ordered and negotiations over manufacturing rights were entered with the French. In May 1940, the weapon was approved as the 20mm M1. However, French drawings were in metric and had to be converted and some minor dimension changes were adapted. This would take a further 9 months and this weapon would be become the M2 or AN-M2.
Now examine that time line. 4 years just to adopt this weapon and that doesn't even consider getting sufficient numbers manufactured along with ammunition and the engineering problems faced by aircraft designers because of the increased size, weight, recoil, installation, etc. All these logistical and engineering factors are very important. If the .50 was totally inadequate, it would have been an easy decision to weigh but that was not the case.
At the Joint Fighter Conference in October 1944, Commander Monroe of the USN Ordnance branch reported the following:
"As it is now, we have the 50-cal. gun which has reached its peak. The only improvements will be minor.(Pyro's note: he was wrong about this as the M3 .50 later increased rate of fire by 50%) The only good increase is to increase the number of guns. So it seems to be just about the right time to look for a better weapon. There are two possibilities here- the one we have and the one we might get shortly. The one we have is a 20mm gun. I think very highly of it. It is a fact, it is one we have here, and it is one in hand. It won't do what the 60 will do, but we haven't got the 60, and we won't have it for a year. So we are gradually working into all our aircraft the 20mm gun. To give you some idea of the 50 versus the 20 and dispel a lot of ideas that have bothered us, I would like to give you a comparison. When somebody goes from four 50's to two 20's, to the layman that means a decrease in firepower. Actually, quite the reverse is true. In the horsepower of the gun, one 20 is equal to three .50-calibers. In the actual rate of fire delivered at the target, one 20 equals three 50's; in kinetic energy at 500 yards, one 20 equals two and one-half 50's.
"That adds up to four 20's equaling twelve 50 calibers, judged by those standards. Of course you have other advantages of the 20. You have the much greater penetration of armor. The 20 will go through 3/4 inch of armor at 500 yards, while the .50 cal will go through only .43. In addition to that you have one more great advantage- that is, you can have longer and more frequent bursts without damage to the gun with the 20 than you can have from the .50 cal. That is important for the strafing airplane, because they are burning up their barrels and ruining their guns on one flight. Sometimes it is long before that one flight is over. They will come down with screaming barrels and get trigger-happy, and then all the barrels are gone in one flight. It should not happen in a 20-mm. (Pyro's note: AAF pilot instructions allow a much longer burst of fire from .50s than from 20mm's) Of course, you have disadvantages. You have a heavier installation, one-half as much ammunition for the same weight. Our standard ammunition in the Navy is 400 rounds in one gun. The Fleet has set up 30 seconds of fire as a minimum requirement for the .50 cal gun. We can't do that with the 20, so we give them 200 rounds. The 20 is lethal enough to get far more results out of that 200 rounds than the .50 will ever do in 400 rounds.
"With the 20 you are putting out a new weapon. Fortunately, we are over the headaches to a great extent in the Navy. The SB2C has led the way with the 20mm. We had an awful lot of headaches getting the new ammunition, the new lengths, etc., and getting the ordnance men to learn how to use the gun and get around the temperamental characteristics. We are over that now, and the majority opinion is very enthusiastic about the 20mm gun. We have at the present time 200 Corsairs going out, at the rate of 50 a month, which will go into action as soon as we can get them aboard the carriers to get an evaluation of the 20mm gun in the Navy fighter. I am personally very anxious for the first report on that, and I think the first time they open up on a Jap fighter, it's going to fly into a million pieces. We have a great cry for the 20mm gun.
"Another disadvantage of the 20 is the time of flight. Out to 500 yards you've got three-quarters of a second as agasint a .62 for the 50. These airplanes go 450 to 500 feet per second, and in one-tenth of a second 35 to 40 feet.
"It also hurts when you try to mix the batteries. I am personally very much against mixed batteries, with teh guns at the present ranges. If the Mark 23 sight does what we want it to do, it is going to push the hitting range out so far that the 50 cal will get to the target a helluva lot ahead of the 20. If our fire control that is coming is as good as we think it is, it is very unwise to mix the batteries. For present battle ranges it is perfectly all right. Of course the Navy is fighting in the Pacific. We have a rather inferior bunch of enemy airplanes. The Japs have played ball with us very nicely all during the war so far and they have refused to improve their armament or their planes as fast as we could expect them to. I have a WAVE in my office who keeps a chart on all Japanese aircraft trying to figure out what the trend is and it is very definitely towards larger armament, heavier guns, more guns and leak proofing and much better performance airplanes. In view of that, it behooves us to get in ahead of them. I feel it is much better to put the 20mm in now, although the 50's are doing a perfectly acceptable job and we could probably finish the war with them. It doesn't make the pilots feel very good to be shooting 50's when the enemy is shooting 20mms, however. Their 20mm is a somewhat inferior weapon, of course. We've got hold now of an experiemental Jap fighter. It has four 20's and two 30-caliber guns. The guns in that airplane are of German design copied by the Japs and they are pretty good guns. They're worth anybody's respect and it is not going to be any fun to come up against an airplane like that with inferior armament.
"We're finding all the time 20mm guns, 37mm and 50 calibers in increasing numbers, in Jap aircraft. I don't know why the Japs stick to the 30 caliber. It is a completely ineffective weapon particularly the way they use it. It might be all right in the fighter if you had 16 of them and got right on somebody else's tail. You might saw them apart. The day of the 30 has long since passed. The Japs stick to it and it's fine from our point of view. In the Fleet we have the SB2C which originally came out with a single .50 turret. Due to the marginal performance, they took the turret out and put twi 30 cal guns in its place. That was a very fine solution as far as the Fleet was concerned. They were delighted with it and have continued to be so. The same comparison holds true for the 30's and 50's as has held for the 50's and 20's. Two 30's are approximately 1/3 to 1/2 as effective as one 50. The two hand-held 30's can't compare to the effectiveness of the power turret, as far as getting on the target and holding your aim and following your enemy around. The Japs are very easily frightened off by those two streams of 30 caliber tracers going out there. The boys are able to scare most Jap pilots by hosing a stream of bullets out there in their general direction. However, it is my firm belief that if the Jap pilot would get over his awe of those tracers and just plow right in, he would have no trouble at all taking the SB2C any time he wanted to with his 20mm guns."
Later in the discussion, Commander Munroe said the following:
"I wonderif 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."
The British went through these same problems but it wasn't as big of a dilemma for them as they were looking at the difference between .30 cal to 20mm. Even so it caused controversy between the different schools of thought that didn't end until the 20mm proved itself well in combat. This wasn't helped because of the bugs that had to be worked out from the problematic first installation of 20mm's in the Spitfire IB. Group Captain Kent wrote the following about the change in firepower that came with the cannon armed Spitfire:
"It was not very long after we received these aircraft that one of our flights was scrambled after a small force of 109s. The Flight Commander, 'Pancho' Villa, got to within 300 yards of one of the Germans and opened fire with his machine guns. Although he could see a number of strikes on the enemy aircraft, his fire was having no visible effect. He then remembered his cannons and, slipping his thumb onto the cannon button, gave a very short burst and was more than a little startled, as was everybody else, when the 109 exploded. As he described it, it looked like an anti-aircraft shell bursting and there was nothing left but a cloud of black smoke and tiny pieces tumblimg to the ground."
A few months later, he had the following encounter:
"I attacked and opened fire at about 100 yards (Group Captain Kent records); it was the first time I had fired cannons for three or four months and I was not prepared for the vibration and loud thud-thud-thud as I pressed the gun button. I quickly let go as if I had been stung! I do not know how many shells I fired, it could not have been many, but it was enough - there was a brilliant flash on the starboard wing root of the 109 and the whole wing came off. The rest of the aircraft hurtled down twisting madly round and around giving the pilot no chance to escape even if he had still been alive, which I rather doubt...
"Not wishing to expose myself unduly to the attentions of the flak gunners on the coast I came down very low and slipped over the seashore at Gravelines. Just crossing my path was a small convoy so I put a burst into the stern of one of the ships which started a fire. On my return to Northold I discovered that I had only fired sixteen rounds out of each cannon - I had not used my machine guns - and I became more convinced than ever of the validity of my argument as to the cannon's effectiveness."
This post is way too long and I should be working on something else. Some improvements in damage and the weapons modeling will be made, but if anybody is thinking that the difference between .50s and 20mm's isn't that big, I guess we're at an impasse. Anyway, I hope some of you found this interesting. I have a tremendous reference library on all this stuff, more than I could ever cite here, but I think those passages are interesting if you haven't read them before. Perhaps it'll give some insights into the differences between what works best overall in the real world versus the game world.
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Doug "Pyro" Balmos
HiTech Creations
Perfect plans, aren't.
