The .45 Auto Rim is an interesting crossover cartridge that unities the performance of the .45 ACP cartridge with revolvers. Despite a long history and periods when no .45 AR revolvers were manufactured, the cartridge is alive and kicking and popular with diehard enthusiasts. Revolvers in .45 AR are simply the finest combat revolvers ever manufactured. The .45 AR, given a target-sighted revolver, is also useful in competition and the hunting fields. Let’s look at the history of a cartridge born of necessity.
After the disastrous failure of the .38 Colt revolver in the Philippines and elsewhere, the U.S. Army commissioned a far-reaching test of handgun calibers. The .45 Colt cartridge had plenty of power, but the Army was looking toward adopting a self-loading pistol. The goal was more to isolate characteristics than choose a specific cartridge. Modern high-velocity cartridges and older cartridges were tested against animals and human cadavers. Included in the trials were the Colt .38 ACP self-loader, .30 Luger, and .455 Webley.
Among the officers involved was a man of great experience against native aboriginal warriors and the Moro alike, Colonel John T. Thompson. Also involved was respected Army doctor Major Louis Antonale LaGarde. The tests showed that small-bore cartridges were distinctly less efficient than the big bores in dropping large steer quickly. The board was especially impressed with the .455 Webley and recommended a new service cartridge of no less than .45 caliber. Colonel Thompson also recommended that the Army train men in rapid fire with the new big bore self-loader. Rapid hits with a heavy caliber were the only reliable means of stopping a determined assailant, he wrote.
The 1911 .45 Colt Government Model self-loading pistol was adopted by the Army, and the rest is history. However, during World War I a shortage of the 1911 caused the Army to consider other handguns. Colt had made perhaps 30,000 .45 automatics prior to World War I, and now envisioned arming up to 1 million men with handguns. Smith & Wesson and Colt were each in production with heavy-frame double-action revolvers chambered in .455 Webley for the British. It was a simple matter to chamber these revolvers for the .45 ACP cartridge.
Since the automatic pistol cartridge had no cartridge case rim for ejection by the star ejector, thin sheet metal clips were supplied. With the .45 ACP cartridges pinned into the clips, they headspaced normally and were ejected by the ejector rod in the normal fashion. The result was the fastest swing-out-cylinder revolver in the world to load and unload. Only the topbreak Webley with its hinged-frame ejection and speedloader was nearly as fast. Ejection was sure. Reloading was rapid.
Even today, there is no revolver faster than a .45 ACP revolver using moon clips on a combat course. The original clips held three cartridges, and two were used to load the revolver. Today, full moon clips holding six cartridges are available. A heavy-frame revolver firing this cartridge is both controllable and accurate enough for any personal defense chore.
While simultaneous ejection of the spent cartridges and the ability to load the revolver even with the muzzle pointed upward were great advantages in combat, when the revolvers were released for surplus sales after World War I, the .45 ACP was not a popular revolver cartridge. The .45 ACP ammunition could be fired in the revolvers without the moon clips; the cartridges had to be picked out by hand.
Peters Cartridge Company created a new cartridge in 1920 that solved this problem. The .45 Auto Rim was simply a .45 ACP cartridge with a revolver rim. The original loading used a 230-grain RNL bullet. The heavy rim allowed ejection of spent cartridges. The head area of the .45 AR is much stronger than the .45 ACP, allowing heavier handloads than could be used in the .45 ACP. Elmer Keith designed a heavy SWC bullet for the Auto Rim.
The affordable, rugged revolvers were popular with outdoorsmen. The .45 AR responds well to handloading. As an example, the Magnus 200-grain SWC gives target-grade accuracy. Be certain to crimp lead bullets with a good roll crimp, as a a taper crimp as used with the .45 ACP will allow bullets to be jarred forward during recoil in the revolver. The Hornady 200-grain XTP is a wonderfully accurate bullet and ideal for this cartridge. The 250-grain XTP is a heavyweight that offers deep penetration. Starline brass offers first-quality brass cartridges, while RCBS dies work well in loading this classic.
The problem is that everyone doesn’t handload. Some fire their AR revolvers only occasionally, so handloading isn’t worthwhile to them. Others wish to have a supply of ammunition for their vintage revolvers, just in case. Enter Jamison Brass and its loaded ammunition line under the Captech banner. Its 185-grain JHP .45 Auto Rim offering is a useful, accurate, cleaning-burning load.
My.45 AR is a custom Smith & Wesson Model 1917 with slim grips and a 2 7/8-inch barrel. This revolver is lighter than most .45 autos, well balanced and brilliantly fast into action. There is no heavy barrel, thick grips or fully adjustable sights to add weight. This isn’t the revolver to use maximum handloads with, but it hits as hard as any .45 ACP with standard loads.
If you wish to handload, you may produce ammunition that hits as hard as any factory .45 Colt loading. A 255-grain SWC at 850 fps will solve a lot of problems. When loaded with the Wilson Combat full moon clips and .45 ACP ammunition, there is no revolver faster to load and unload. This revolver is among the best personal defense firearms I have owned. I often carry it in a Don Hume belt slide. The moon clips are fine for most uses, but the Captech International loads are more convenient and offer real power in a defensive handgun. The Captech loads are reliable and accurate, and they burn clean and hit hard. That is all we can ask. Jamison Brass also offers loadings in .45 ACP and .45, among others.
Have you tried Jamison brass? What do you think of Captech’s ammunition? Share your experiences in the comment section