.45 ACP vs .45 Auto Rim

[7075-T7]

I was looking at .45 revolvers and noticed that there is the standard .45acp round and .45 auto rim's, what's up with the auto rims?

[joe817]

This is going back a ways, but if I remember correctly, they are the exact same cartridge dimensions except for the rims.

It was developed principally for the S&W and Colt 1917 model revolvers to eliminate the need for half moon clips needed for .45 acp.

[7075-T7]

ooohhhhh, that makes sense. Buffalo bore has some reg and +p which is about $10 more a box, probably for the odd case. thanks!

[threoh8]

What he said.
The halfmoon and later fullmoon clips work well enough, but some people didn't like working with them. Taking the cases out of the clips before reloading and then putting loaded round in the clips just added steps.
The clips also introduce another variable when people are looking for the last little bit of accuracy.

[mbw]

Yeah, the above posters are correct.

I am looking at a box, Remington, that I bought back in the 70's. Every loading that I have seen is a 230 gr lead. They shoot great in the old revolvers and would also be good in the newer S&W 45 ACP revolvers.

[Keith B]

Also, don't get .45 auto/rim confused with .45 Long Colt, which is what is shot in a lot of single-action 'cowboy' guns.

[Houston1944]

I have a S&W 625 45acp and reload both acp and auto rim, using the same data for both. I cannot remember if it was in the manual or if I read it somewhere else, but I am under the impression that I should not use 230 gr bullets in this revolver. Since this revolver is one of the most accurate handguns I have ever owned and I don't want to take a chance on causing any damage to it, I only shoot it with 185 and 200 gr bullets.

I started reloading this caliber before I discovered the plastic moon clips. If I had known about the plastic clips a few years earlier I probably would not have purchased the brass and caliber setup for the auto rim.