Perfect Packin’ Pistol Part 4

The fourth cartridge in this series is from Smith & Wesson, chambered in a swing-out cylinder double-action revolver — the .45 Auto Rim. The United States Military had adopted the .45 ACP Government Model 1911 three years before WWI started and six years before we entered the conflict. Still we were not ready. Since there weren’t enough 1911s to go around and they couldn’t be produced fast enough, there had to be another solution. The ammunition, .45 ACP, used in the 1911 is rimless which means there’s nothing to catch on the rear of the revolver cylinder for head spacing nor for the ejector star to engage for extracting should such ammunition be used in a revolver.

Joseph Wesson, president of S&W at the time, came up with the ingenious idea allowing Smith & Wesson’s N-Frame 2nd Model Hand Ejector chambered in .45 ACP to work successfully. His idea was the half-moon clip. This clip accepted three rounds and when placed in the cylinder provided proper head spacing as well as prevented the cartridge from moving forward in the cylinder. Placing two of these loaded clips in the S&W cylinder not only provided for the use of semi-automatic cartridges in revolvers but also resulted in very quick reloading if the clips were pre-loaded and also positive unloading. Thus the problem was solved and many soldiers of the American Expeditionary Force were armed not with Colt 1911s but with either a Colt 1917, which was a New Service chambered for the .45 ACP, or a Smith & Wesson 1917/2nd Model Hand Ejector.

A Star Is Born

After the war, as usually happens, these new Colt and Smith & Wesson sixguns became popular with civilians as well as law officers. Now it was time for someone else to come up with another good idea to allow cartridges — sans half-moon clip — to work in either model. This time it was a worker at Peters Ammunition, now part of Remington, who came up with a logical solution in the early 1920s. The simple answer was to put a rim on the rimless .45 ACP brass. The .45 Auto Rim was born.

Most revolver cartridges have a rim thickness of 0.060″-0.065″ but the .45 Auto Rim required a rim of 0.090″ to take up the head space provided by the half-moon clips. There is no doubt the .45 Auto Rim has a rim and it is quite an interesting-looking cartridge with its stubby length and thick rim. Smith & Wesson has always taken the .45 Auto Rim cartridge seriously, offering numerous models over the past 90-plus years. The 5½” 1917 Model was not only offered in military versions but commercial models as well, then after World War II it was upgraded to the 1950 Military and the 1950 Target and then the 1955 Target followed. In later years the 1955 Target became the Model 25-2 and has also been joined by the 625 series of stainless steel sixguns.

It appears there were no factory original 4″ Smith & Wessons chambered in .45 ACP/.45 Auto Rim until well after World War II. The 1950 Target Model .45 is mostly found with the lightweight 6½” barrel, however the 4″ version is reported as extremely rare. The lightweight-barreled 1950 Target became the Model 26 in 1957. I cannot find any documentation of an original 4″ 1955 Target chambered in .45 Auto Rim, however there may be some S&W collector out there who has one. The heavy-barreled 1955 Target became the Model 25 in 1957. It is reported about 10 or 12 were made with 4″ barrels and round butts for the CIA, however these have not been verified as factory original.

Load and Holster

One of my favorite bullets for the .45 Auto Rim was designed by Ray Thompson in the early 1950s. At the time he actually designed four great bullets, namely #358156 for the .38/.357, #429215 and #429244 for the .44 Special and then later for the .44 Magnum, and the #452490 for the .45 Auto Rim. All of these are semi-wadcutter, gas-check designs and the latter was for his Smith & Wesson 1950 Target .45 Auto Rim. It weighs 254 grains in my alloy and also works well with the .45 Colt. In fact I use it for hunting loads in a .45 Colt Ruger Blackhawk. With this heavy bullet in the .45 Auto Rim 13.0 grains of #2400 gives me just under 1,000 fps. Again caution is necessary and these loads should be only used in modern .45 Auto Rim sixguns in excellent shape.

The .45 Auto rim is more efficient than the .45 Colt with most loads because of its reduced case capacity. The .45 Colt is, of course, the cartridge of choice when heavy duty loads are desired and the sixgun is strong enough to take advantage of the large case capacity while the .45 Auto Rim is better in standard-size cylinders.

An extra added bonus for the .45 Auto Rim is the fact it works quite well with the range of jacketed bullets designed for the .45 ACP. The lightweight 185-grain jacketed hollow points can easily be loaded to over 1,000 fps with 8.5 grains of Unique, resulting in an excellent choice for varmint shooting or small game hunting. With a 230-grain typical hardball bullet, 7.0 grains of Unique gives about 860 fps which is plenty powerful for most uses.

A second extra added bonus is the fact we can go right back to the beginning and use any of the revolvers chambered for the .45 Auto Rim with .45 ACP brass in half-moon or full-moon clips — that’s versatility if I’ve ever seen it!

Subscribe To GUNS Magazine

Purchase A PDF Download Of The GUNS Magazine July 2021 Issue Now!