to allow the revolvers to chamber the .45 ACP cartridge.
Chambering a revolver for the .45 ACP cartridge isn’t a problem. Ejecting the rimless .45 ACP cartridge presented more difficulty. The now-famous moon clip solved this difficulty. The thin sheet metal clip was originally issued in pairs, with two three-round clips needed to fully load the revolver. After the gun load was fired, a rap on the ejector rod threw all six cases out at once. Naturally, fired and unfired cases would be ejected simultaneously. This system created the most efficient loading and ejecting system ever used in a revolver. No matter what the angle of the muzzle, there was no possibility of the spent cases jamming under the ejector star. All were ejected at once.
Also, a moon-clipped revolver is the fastest revolver of all to reload. Whether the muzzle is pointed up or down, it is possible to quickly load the .45 ACP revolver with moon clips and remain in business. It seems doubtful this system would have been developed outside the crucible or war, but it worked well. How much use the 1917 revolvers saw is another matter. Used they were, by military police, drivers, and tank personnel, while front line troops received the lion’s share of 1911 self loaders. If I could not have gotten my hands on a 1911, I would not have felt naked with a good 1917. I am sure a few doughboys preferred the familiar revolver.
The author often totes this 1917 Smith and Wesson when hiking or simply spelunking.
This photograph illustrates the three types of .45 ACP/AR headspacing. The cartridges at the top are .45 ACP rounds, held by a two-round moon clip. On the bottom left are two .45 ACP cartridges simply loaded in the chamber, and finally two .45 AR cartridges. The author feels the .45 AR solution makes the most sense.
This Smith and Wesson 1917 is fast handling and powerful. The revolver has been Meta Life plated and fitted with Ajax stag grips. Carried in a Tucker belt slide, this is as good as it gets in a defensive revolver.
After the war, many 1917s were sold as surplus. Some went to bank guards, others went to the fledging US Border Patrol, and quite a few were used by outdoorsmen. After all, here was a good double action big bore revolver at a modest price.
Most of the shooting public, however, did not care for moon clips. They were seen as a nuisance at best. Since the .45 ACP cartridge headpaced on the case mouth and not on the rim, the 1917-pattern revolvers could be fired without the clips, but the cases had to be picked out one at a time, a tedious process. Remington introduced a solution in 1920: the .45 Auto Rim. The .45 Auto Rim is basically a rimmed .45 ACP, with a rather thick head in relation to the short case. It is not interchangeable with the dimensionally similar .45 Schofield. Enterprising handloaders (is there any other type?) learned the .45 AR offered a couple of advantages over the .45 ACP, other than the obvious simplicity of chambering without the aid of moon clips: the case head is stronger and offers more support, allowing heavier loads, and the .45 AR is well-suited to lead bullet loads, something that could not always be said of the .45 ACP round as fired from the 1911. The original .45 AR factory loading produced 830 fps with a 230-grain round nose lead bullet. Today, to the best of my knowledge, the .45 Auto Rim is loaded by Georgia Arms on a standard basis and is available from custom maker Quality Cartridge as well. (Note that as of this writing, most ammunition makers are experiencing heavy delays and backorders.) The tried-and-true Remington loading has, regrettably, disappeared from Big Green’s catalog, and it is doubtful whether it will ever reappear.
The best news to come along in some time is the availability of .45 Auto Rim brass from at least one manufacturer: Starline. With these high quality cartridge cases, the .45 Auto Rim fan has a reliable resource and may reasonably stretch his .45 AR to accommodate heavy loads.
The Star Bullets 185-gr. SWC HP performed beyond expectation. This is excellent expansion at low velocity.
Left to right, the 185-gr. Star bullet with experiments in seating depth, the 200-gr. Speer Gold Dot in .45 AR brass, the 240-gr. Sierra JHP and the 230-gr. XTP, all good loadings for specific uses.
The Sierra bullet at left has been deep seated; no need to worry about feed reliability in the revolver. But be certain to reduce powder charge when experimenting with deeper seating of heavy bullets.
At maximum velocities, the Speer Gold Dot, left, gave good results and the Sierra 240-gr. JHP shows uneven expansion. The 230-gr. weights are best suited to standard .45 ACP velocity.
.45 AUTO RIM LOAD DATA
Note: All loads loaded on RCBS equipment, all primers standard Winchester Large Pistol primers. All brass is Starline. All handloads listed were fired for testing in the Smith & Wesson 1955 target revolver.
JACKETED BULLETS
* This is a good load, very accurate, but the bullet is designed for the .45 Colt. I don’t believe you will see any expansion on game at this velocity. But just the same it is among the most accurate .451-inch bullets, not only in the .45 AR but in my .45 ACP and .460 Rowland pistols as well. It certainly has enough penetration for most purposes.
LEAD BULLETS
The bulk of .45 Auto Rim ammunition was fired in the 1917 revolvers. Elmer Keith designed a semi-wadcutter bullet just for the short chambers of this revolver (238-grain Lyman #452423 – now sadly out of production but occasionally available on the used market). Short chambers are the one real failing of the .45 AR. The 1917s and even some modern 625s will not accept the longer 250-grain bullets, so the 200- to 240-grain SWCs are used. The 1955 Targets usually accept heavier bullets. Also, some of the modern runs of 625s will not function properly without moon clips when firing the .45 ACP. They simply will not headspace correctly unless .45 AR or clipped .45 ACP cartridges are used.
When the heavy barrel 1955 models came along, handloaders worked up combinations that gained a new respect for the .45 AR. With its heavy barrel, target stocks and full length ejector rod housing, the new revolver was heavier and more pleasant to use than any 1917. The .45 AR’s stronger head and the fact that the cartridge case is better supported in the revolver than the .45 ACP in the 1911 autoloader allowed the cartridge to considerably outperform the .45 ACP. The .45 AR is about as strong as a safe load in the Colt SAA in .45 Colt. For medium game and as a defense load, this is an outstanding caliber.
I appreciate the combat advantages of a .45 ACP revolver with moon clips, and have used this combination successfully in bowling pin shoots. But with top accuracy and hunting more my focus these days, I use the .45 AR for the most part. For informal shooting I sometimes use the more common .45 ACP brass without clips, although some revolvers lose accuracy potential when fired in this manner due to inconsistent headspacing. I have read comments from writers in the popular press who have stated that
