.45 Auto Rim In .45 Colt

by
posted on April 25, 2014
** When you buy products through the links on our site, we may earn a commission that supports NRA's mission to protect, preserve and defend the Second Amendment. **
qanda2015_fs.jpg (2)

Q. Can you safely shoot a .45 Auto Rim cartridge in a revolver chambered for a .45 Colt? A buddy of mine gave me some the cartridges, but I don’t have a gun in .45 Auto Rim. I do have a .45 Colt, though, and it looks like it should work.

A. I would not encourage anyone to attempt to fire a .45 Auto Rim cartridge in a cylinder chambered for .45 Colt. Aside from differences in the dimensions of the cartridge case, the Auto Rim round has a significantly thicker rim, approximately 0.090" versus approximately 0.060". This could certainly cause headspace and functioning problems. If the revolver in question is supplied with a separate cylinder specifically for the Auto Rim cartridge, there should be no problem. A number of firearm manufacturers have over the years offered .45 revolvers with dual cylinders, one for .45 Auto Rim or .45 ACP cartridges and one for .45 Colt.

-Reid Coffield

Originally published September, 2006

Latest

Winchester Super Match 01
Winchester Super Match 01

Competition Ready: Winchester's New Super Match Ammunition

Winchester Ammunition has answered the call of competitive shooters with its new Super Match lineup, comprised of cartridges tailored to perform in a variety of events.

A Brief Beginner's Guide to Buying a Defensive Handgun

After running a gun shop and an indoor range for more than a few years, one American Rifleman contributor has a few tips for those looking to buy their first handgun.

Gun of the Week: Wilson Combat Bulwark

Wilson Combat has long been known for its custom work on 1911-style designs, but the company also develops its own firearms, and one of its latest in-house creations is the new Bulwark.

The Armed Citizen® Sept. 4, 2026

Read today's "The Armed Citizen" entry for real stories of law-abiding citizens, past and present, who used their firearms to save lives.

NFA Wait Times Continue to Drop

In early 2021, it took the ATF about 280 days to process a Form 4 NFA transfer. In August 2026, using the recently implemented eForms system, that wait time had dropped to only nine days.

Pelican Air Carry-on Case Review

An industry staple just made air travel more convenient.

Interests



Get the best of American Rifleman delivered to your inbox.