.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

Dead Air Rxd910ti Suppressor F
Dead Air Rxd910ti Suppressor F

"9 mm Optimized, But 10 mm Capable:" Dead Air's New RXD910Ti Suppressor

The new Dead Air RXD910Ti harnesses the technology of the patented Triskelion baffle system to make for a 9 mm-optimized silencer that is also capable for use with 10 mm pistol cartridges and more.

Revisiting A World War II Marine’s Story

Secretary of War Pete Hegseth, in his speech to 800 assembled generals, admirals and senior enlisted at Quantico, Va., on Sept. 30, 2025, quoted Eugene Sledge from his timeless classic With The Old Breed published in 1981.

Review: Leupold Rendezvous Soft Cases

Looking for something better than a cheap nylon bag, but don’t need it armored for air travel? Leupold has you covered.

Preview: Hiperfire Hipertrain

Hiperfire’s Hipertrain is a cast aluminum housing into which the AR-style trigger system, safety selectors and pistol grip of the user’s choice (none of which are included) can be installed to create a trigger demonstrator/dry-fire trainer

New For 2026: Kimber 2K11 Comp

Kimber increased its 2K11 product line with the addition of two models with single-port compensators.

AR-15 vs. Bullpup Rifles: Which One Is Right For You?

Though bullpup-style rifle designs have become popular elsewhere in the world, they aren't nearly as popular with the American shooting public as the ubiquitous AR-15.

Interests



Get the best of American Rifleman delivered to your inbox.