45 Auto Rim brass

[Char-Gar]

This information is welcome, and all good-to-know stuff. I also have two 625s in the 4" Mountain Gun configuration in .45 ACP, but honestly the thought has never occurred to me to try them with anything other than full moon clips. But just a slight tug back to the original subject, it was about 1917 model revolvers, or so I thought.

It was indeed, but the issues of using cut off 45 Colt cases remains the same. If anything the issues are worse in a 100 year old revolvers with a century of use and century old metallurgy.

[Tackleberry41]

The cut down 45 colt would fit, yes. But doubtful it would fire, there would be a large gap between the back of the case and the firing pin. The ACP and the moon clip is the same thickness as the auto rim, rim. But thicker than a 45 colt.

I have cut down 45 colt and 454 casull cases to fit in a 45 acp conversion cyl in my blackhawk. You cant roll crimp an ACP case to prevent recoil from pulling the bullets out under 460 rowland recoil. I did try some 45 AR cases, just out of curiosity, not they wont fit, rim is to thick. AR is to thick for a blackhawk, 45 colt is to thin for the old S&W.

I bought a bag of the AR cases, not horribly expensive. And work with a speed loader. I have a pile of full moon clips, but wanted the AR cases just to have them.

[Harter66]

There is .0227 difference in the AR and Colts rim . The Schofield shares the rim thickness of the Colts but is slightly larger dia .

The Colts neck dia is .480 vs the ACP at .473 SAMMI . So the Colts is larger dia going in plus our cast bullets up to .458 vs spec of .451-2 .

If we bide by the light taper , no , just enough crimp to remove the flair AND we have a proper 45 ACP chamber then at least for the purpose of headspace this should be a non-issue .
If a revolver cylinder will accommodate a moonclip and/or any rimmed case and the Colts , Schofield , 454 , 460 or Savage , 308 , Mauser or 06' families trimmed to .898 then again it shouldn't be an issue because the larger diameter case with the same sized bullet is head spacing on the mouth NOT on the rim .

The difference in thickness of the AR and Colts family rims is .0227 inches unless I missed something and my Winchester , Starline , Rem or AP brass doesn't have the tapered web I think it does I don't believe it will thin enough fast enough to be a significant threat to case failure . We're looking at Colts with a working max at 14,000 psi and ACP at 21,000 psi where Ruger only loads run up to 25,000 without​ case failures .

Someone mentioned loading Rowland levels ......why...... Anyway with virtually unlimited seating length it's a non-issue to burn a little more powder and keep the pressure down . Most ACP cylinders are way longer than the max OAL of an ACP .

This brings us to function . Making the presumption that we have a cylinder that correctly headspaces on the mouth of an unclipped ACP . The Colts do wander and the cylinder doesn't move freely the first pass when the bottom half of the case is sized small the 2nd go is better but I would still consider it a stop gap not a fix .

My next project is to Schofield an APC revolver I have invested a great deal of time in this exploration .

[Battis]

If you measure the length of a 45 ACP case (a case that headspaces on the case mouth) and cut a 45 Colt case to the exact same length (and size it), basically you're making up for the thinner rim of the 45 Colt case with the case mouth. The case will headspace on the mouth, and the rim will be used for nothing but extraction. The distance from the firing pin to the primer will be the same. It's basically a 45 ACP case with a rim. I primed a few cases that I made and they worked fine. I also posted the same question on the Smith & Wesson forum and apparently it's not a new idea, it's safe, and it works fine with loaded ammo. Some posters wondered why I'd ruin perfectly good 45 Colt brass when 45 AR brass is readily available. I have some 45 Colt brass that I don't need so I figured I'd try it.

[Harter66]

I had some with mouth splits .