.45 AC with serated rim

Can anyone please explain the reason for the serated edge on the rim of the .45 AC cartridge in the photos?



I would say that someone modified the case to approximate a .45 Auto-Rim, for use in a Colt or S&W Model 1917 revolver.

I can’t imagine going to all that bother and then not shooting it.

I have a simular serated edge on the rim in cal 9x19mm Para. It seems as Jon C. already noticed that it is done to make a pistol cartridge suitable for a revolver. The 9mm Pare would fit in a .380 Webley revolver.
I beleve the primitive but effective conversion was made during the WWII period.


Jon is probably correct about why this was done. I have a couple of these also, done differently from each other but to the same result. I also have a few from South Africa in 9mm Parabellum caliber, probably done to put into the Webley or Enfield .38 S&W (.380 British) caliber revolvers.

The problem with doing this for a 1917 revolver, is that those revolvers have a larger gap to accomodate the half-moon clip. They are, however, correctly chambered for the .45 Auto cartridge with the case headspacing on the case mouth. therefore, despite the gap they should headspace o.k. The home-made rims would probably not even bear against the back of the cylinder. However, then, the only possible reason for “squishing” out the rims would be with the hope that the revolver’s extractor would work. If the alteration was done abroad, by insurgency groupls, of course it may be they weren’t altered for S&W revolvers at all, but rather to shoot in .455 Webleys or any other large caliber revolver they could cram them into. II don’t honestly know if you can chamber one in a .455 or not - have never tried it and don’t own a .455 to try one now). It is not necessary to have clips to fire .45 ACP rounds in most US revolvers. I used to do that with a Smith and Wesson Model 1955 Target, and I simply had a wood dowel I used to knock out the cases. Loading with half moon clips was easy, and loading THE half-moon clips was easy, but taking the empties out of the clips was terrible. They didn’t have the numerous little unloading gadgets they sell today for the purpose. For practice, the dowel method was easier.

Thanks for the answers which give a logical explanation for the serated rim.