When asked about a .45 Cal. handgun used in the second world war, what comes into the mind of a history buff is the Legendary M1911A1 Pistol. But there is this “other” .45 Cal. handgun and it is NOT an automatic pistol.
The M1917 Revolver (formally United States Revolver, Caliber .45, M1917) was a U.S. six-shot .45 Cal. double action revolver . It was adopted by the U.S. Army in 1917 to supplement the standard M1911 .45 ACP Semi Automatic Pistol during World War I. Afterwards, it was primarily used by secondary and non-deployed troops. There are two variations of the M1917, one from Colt and one from Smith and Wesson (S&W).
The Colt M1917 and the S&W M1917 Revolvers
Before the first World War, Colt has been making a revolver for the U.S. Army called the M1909, a version of their heavy-frame, .45-caliber, New Service model in the rimmed .45 Long Colt. to supplement and replace a range of 1890s-era .38 caliber Colt and Smith and Wesson revolvers that had demonstrated inadequate stopping power during the Philippine American War and the Moro pacification campaign in Mindanao.
Since then, American personnel assigned in the Philippines would insist on carrying no less than a .45 cal. sidearm, and the M1917 in lieu of the M1911 pistol seemed to fit the bill. An American guerrilla commander in Mindanao, Capt. Clyde M. Abbott carried one during his days in Balingasag, Mis. Or.
The Colt M1917 Revolver was essentially the same as the M1909 with a cylinder bored to take the .45 ACP cartridge and the half-moon clips to hold the rimless cartridges in position. In early Colt production revolvers, attempting to fire the .45 ACP without the half-moon clips was unreliable at best, as the cartridge would slip forward into the cylinder and away from the firing pin. Later production Colt M1917 revolvers had head spacing machined into the cylinder chambers, just as the Smith & Wesson M1917 revolvers had from the start. Newer Colt production could be fired without the half-moon clips, but the empty cartridge cases, Just like the S&W when fired sans half moon clips the spent brass casing had to be ejected with a device such as a cleaning rod or pencil, as the cylinder extractor and ejector would pass over the edge of the rimless cartridges.
Although both revolvers were called the M1917, their mechanism are not interchangeable unlike the M1911A1 Pistol that was produced by Colt, Remington Rand, Union Signal and Switch, Ithaca and Singer. Both revolvers use the same .45 cal. ACP in half-moon clips and would fit in the same holster.
Top revolver is the Colt, the Smith and Wesson at the bottom. Note the .45 ACP ammo on half-moon clips as the .45 ACP ammo was designed for the M1911 Pistol (also used for the M1 Thompson)
Photo Credit: Smith & Wesson Forum; David Wilson