45 Auto Cartridges (Chap 3 of H, W & S)



I finally got myself “History of Modern US Military Small Arms Ammunition Vol 1 Revised” by Hackley, Woodin and Scranton recently and currently reading Chapter 3 about the 45 Auto. I have two questions which I hope someone can help with.

  1. At bottom of p.20 and top of p.21, the authors talk about “Frankford Arsenal was authorized to convert 8,000 revolver cases for use in automatic pistol cartridges, this being completed by November 1906”. And “A cartridge without headstamp, narrow extractor groove and more straight-sided bullet may be an example.” I would like to know is there any other differences that one could tell one of these cartridges? I sure would like to see a photo. I suspect that they are rare cartridges?

  2. On pp25-26, the authors discuss the special reduced velocity Model 1911 ball cartridge which was loaded “as early as 1917”. It was made to have a muzzle velocity of about 600 fps and was used to test helmets. Would anyone know what the helmets were made of or would know where I could find the helmet construction details at that period?

Thank you. (I should have bought this book a long time ago).

Ian B.


From Bady’s book, “Colt Automatic Pistols.”

There’s much information that I will condense greatly. In 1904, Colt began development of a .45 auto pistol (which became the Model 1905) using a .45 Colt case, which they modified to rimless. It was too long and the bullet was too heavy. Colt then cut the case length to 0.9" and went to a 200 grain RN bullet at 850 ft/sec. Manufacture of this cartridge was then farmed out to Winchester for production in quantity to meet Colt’s needs for pistol development. Army Ordnance was aware of the events at Colt, and was very interested. There was some activity in producing this cartridge at Frankford Arsenal beginning no later than early 1906, but just how this was done is not stated. FA may well have modified .45 Colt cases. The number made by FA was unstated. This production was for pistol trial use. In practice, the commercial (Winchester?) round produced fewer malfunctions than the FA round. Pistol inventors could buy FA ammunition for $2.87/100, but could also use the commercial round.

What was apparently the first production of what was later to become the M1911 .45 Ball was a 100,000 round Army Ordnance order made by UMC, delivered in September 1908(?), under new (1907) Ordnance specifications requiring a bullet no less than 230 grains and a 25’ velocity of no less than 800 ft/sec. This round was also intended for pistol trial use.

There is a great deal more on the development steps resulting in the Colt Model 1911 and its adoption by the US Army to be found in the book. Doesn’t answer the question but does provide a timeline of sorts. I’ve not heard of a helmet testing round. Off the top of my head, the idea makes very little sense to me for several reasons.


Most large countries that produce ammo for their armed forces have made helmet test rounds (Stahlhelmabnahme patrone in German). I suspect they gave a two way test - see what protection the helmet gave the troops, and see if their pistol (SMG) rounds would punch the enemies helmet. I don’t now if that double-purpose was the intent or not, but it would work out that way.

Body armor of any type is usually subjected to penetration tests before patterns, materials, etc. are finalized.


HWS is a well researched series of books (two down and one to go). If you go hunting in RG 156 at the National Archives, you will find Frank Hackley’s footprints all over the place.

Would anyone know what the helmets were made of or would know where I could find the helmet construction details at that period?

Yes, there was a .45 round designed for quality control testing of helmets in World War I. The helmet in question was the “British” type and while deficient from the standpoint of head protection; it had the advantage of being easily produced. Over 2.7 million helmets of this type were produced by American manufacturers before the end of the war. The helmets were composed of .036” alloy steel. The helmet was designed to stop a .45 caliber pistol ball traveling at the rate of 600 feet per second at a distance of 10 feet. This was meant to imitate shrapnel as 7 out of 10 soldiers wounded in the war were injured in this way.

Source: America’s Munitions by Benedict Crowell. GPO: 1919. Pages 222-224.


I have no doubt there was a helmet proof testing .45 round. My misgivings are:
(1) How does a .45 bullet at 600 ft/sec simulate shrapnel? Shrapnel fragments come in all shapes and sizes, at widely differing velocities, and can strike in very different attitudes. All of these factors can make a great difference in penetration ability. There would necessarily have been some sort of simulation study required to establish that a conventional .45 bullet at 600 ft/sec provided the same penetration in a helmet as the 50th, 75th, etc. percentile of random battlefield shrapnel. Possible, but I wouldn’t trust it much.
(2) Notwithstanding the above, once the helmet shell’s steel alloy, thickness, and hardness have been established sufficient to stop the .45 bullet, then even primitive manufacturing QA should be able ensure that all helmets are manufactured to the same minimum acceptance standard. Therefore little additional shooting would be required. Perhaps the ability to maintain a minimum standard of manufacture was not well developed at that time, necessitating frequent shooting (actually, a form of destructive testing). It’s sort of like crash testing 5% of a certain car model coming off the production line to establish the model’s safety performance. It’s just not necessary, once a few have been crash tested.

I can’t see that there would have been a need to do more than minimal destructive testing on helmets, as it’s much easier, cheaper, and just as effective to do some hardness tests and thickness measurements to establish lot acceptance.

Wasn’t there a flap about the adequacy of certain production runs of U. S. Army Kevlar helmets to provide proper ballistic protection a few years back?


Remember that “shrapnel” in its classic definition refers to spherical metal bullets or the projectile containing them, not to shell fragments. In this sense a .45 auto bullet would be a reasonable simulation of the effect of such objects. Jack


U.S. Helmet designs and construction, materials makers and history are covered in great detail in Chris Armold (ArMold, not ArNold) “Steel Pots.”