M1917 Revolver Country United States Type Revolver Manufacturer Colt Introduction 1917 Specifications Weight 2.5 lb (1.1 kg) (Colt) 2.25 lb (1 kg) (S&W) Length 10.8 in (274 mm) Barrel length 5.5 in (140 mm) Cartridge .45 ACP Action double action, solid frame with swing-out cylinder Feed system six-round cylinder, loaded singly or with two three-round half-moon clips Sights blade front sight, notched rear sight

The M1917 Revolver (formally United States Revolver, Caliber .45, M1917) was a U.S. six-shot revolver of .45 ACP caliber. It was adopted by the U.S. Army in 1917 to supplement the standard M1911 .45 ACP semi-automatic pistol during WWI. Afterwards, it was primarily used by secondary and non-deployed troops. There were two variations of the M1917, one from Colt and one from Smith & Wesson.

U.S. civilians arms companies of Colt and Remington as well as other companies were producing M1911 pistols under contract for the U.S. Army, but even with the additional production there existed a shortage of M1911s. The interim solution was to ask the two major American producers of revolvers to adapt their heavy-frame civilian revolvers to the standard .45 ACP pistol cartridge. After the First World War, M1917s became popular on the civilian market. Some were military surplus. Others were newly manufactured. The M1917 also remained in US service through WWII and was still in use with some reserve units as late as the Vietnam War