.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

man inspecting a cartridge with a magnifying glass
man inspecting a cartridge with a magnifying glass

The Drawbacks of Being a Numbers-Oriented Gun Guy

Like any hobby or pastime that is in any way even vaguely related to machines or technology, firearms attract a (possibly) disproportionate number of “right-brained,” STEM-oriented personalities who like numbers.

First Look: MDT Hand Cannon Slingshot

Slingshots are fun, but they can also be a legitimate backup defensive tool—in 2023, a 13-year-old Michigan boy saved his 8-year-old sister from being kidnapped by using a $3 slingshot to fire a marble and a rock at the assailant, striking him in the chest and head.

The LCP Meets Magpul: Ruger's LCP Max with Magpul's EHG

Over the years, Ruger has enhanced its LCP with the introduction of the LCP II and LCP Max. New for 2026, Ruger is offering a new version of the LCP Max with the addition of a Magpul Enhanced Handgun Grip.

Review: 945 Industries Q.A.P. Series Off-Body Carry Bag

Off-body carry can be somewhat controversial, but choosing the right gear can go a long way toward successful carry. One good option is the Q.A.P. Series of bags from 945 Industries.

At 75, CCI is Offering Even More

In 2026, CCI Ammunition—formally Cascade Cartridge, Inc.—marks its 75th anniversary with a fitting tribute to innovation and American ingenuity.

Gun of the Week: Powder River Precision Rubicon Icon

Powder River Precision has taken the basic Ruger 10/22 rifle concept and enhanced it with its Rubicon Icon design.

Interests



Get the best of American Rifleman delivered to your inbox.