.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

Armasight Operator thermal riflescope
Armasight Operator thermal riflescope

New for 2026: Armasight Pro Series Thermal Platform

Armasight launches a professional-grade thermal-imaging platform designed to perform.

KelTec Launches KelTec Direct

KelTec begins its 35th anniversary celebration by launching KelTec Direct.

New for 2026: CVA Scout XP and XP-SB Rifles and XP Pistol

CVA expands its Scout line to include two single-shot rifles and a single-shot pistol.

Preview: Winchester After Hunt Dog Bed

Named after John Olin’s famed hunting dog, the King Buck product line exists within the larger Winchester Pet brand to showcase the company’s most deluxe offerings, and the After Hunt Dog Bed is a prime example of the line’s quality.

Review: CZ USA P10 Ported

CZ expanded its popular line of P10 handguns with a specially configured model that features integral barrel ports just behind the muzzle to aid in recoil management.

Keeping The Wilderness Quiet: Bergara's BTi30 Suppressor

Bergara joined the growing crowd of suppressor manufacturers in 2026 with its BTi30 design.

Interests



Get the best of American Rifleman delivered to your inbox.