GMan- Actually I have fired an automatic 20mm from a pedestal mount on a couple of occasions. Not that I garnered any special insight, but it certainly is more impressive in person than in a book or on tv.
Feel free to send me anything you think would be helpful. In this particular case, I do have ballistic and armor penetration tables for the 1944 M2 50 Cal. I don't have the figures handy, but it won't even come close to penetrating 1 inch at 1600 yards. At 1000 yards I believe it will penetrate around a 1/4 inch at 0 degrees.
Hang- sometimes you'll see figures that put the M2's rate of fire down in the 500-650 RPM range. This is correct for the standard heavy barreled M2 but not for the aircraft version.
Here's a quick and abridged obscure history lesson for those interested in this kind of stuff...
In 1939 the Air Corps drafted a requirement for a weapon citing characteristics that the .50 was capable of meeting but with a rate of fire of at least 1000 rpm. The M2 could only do 500-600 rpm depending on the mount. Colt spent a couple years working on a design, but had severe problems and nothing came of it.
Meanwhile, in 1940, the Springfield Armory lightened components of the M2 and added double driving springs in place of a single spring. This increased the rate of fire up to 800 rpm. It didn't meet the initial requirement, but it was still a good improvement. The downside to this was greatly increased barrel erosion. In early 42, the National Defense Research Committee went to work to find a way to reduce barrel erosion. After two and a half years of research, they came up with a special alloy to line the barrel with.
Meanwhile still, the High Standard company was working on increasing the M2's rate of fire even more, but had to keep the changes to a minimum. They made some promising innovations but could not meet test requirements. So in 1943, the Ordnance Dept gave up on the idea of having the new design keep interchangable parts with the M2, but they still wanted the same basic mechanism to be used. Frigidaire started working on this project and had a successful model by the autumn of 44. This model had a lot of redesign and advancements, a couple taken from High Standard's earlier work. Rate of fire was increased to 1200 rpm and it was ordered into production as the M3. However, only 2400 were completed before the end of the war.
The Ordnance Dept found that they could also incorporate some of the improvements of the M3 into the M2. These improvements would boost the rate of fire to just over 900 rpm. Only 8000 were produced- a quarter of the initial order, due to the M3 production progressing quickly.
BTW, I have a Frigidaire refrigerator and both the icemaker and water dispenser could really use a faster rate as well.
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Doug "Pyro" Balmos
HiTech Creations
"If it's stupid but works, it's not stupid."
