Engineering:M1917 revolver

M1917 Revolver
Smith & Wesson 1917 with moon clips and two auto rim cartridges
Type	Revolver
Place of origin	United States
Service history
In service	1917–Present
Used by	See Users
Wars	World War I World War II Korean War Vietnam War (saw combat with the "tunnel rat" units)
Production history
Designed	1917
Produced	1917–1920
No. built	~300,000 total (c. 150,000 per manufacturer)
Variants	Slightly differing versions of the M1917 were made by Colt and Smith & Wesson (shown above).
Specifications
Mass	2.5 lb (1.1 kg) (Colt) 2.25 lb (1.0 kg) (S&W)
Length	10.8 in (270 mm)
Barrel length	5.5 in (140 mm)
Cartridge	.45 ACP (11.43×23mm), .45 Auto Rim (11.43×23mmR)
Action	Double action, solid frame with swing-out cylinder
Muzzle velocity	760 ft/s ( 231.7 m/s)
Feed system	Six-round cylinder, loaded singly or with two three-round half-moon clips
Sights	Blade front sight, notched rear sight

The M1917 Revolvers were six-shot, .45 ACP, large frame revolvers adopted by the United States Military in 1917, to supplement the standard .45 ACP M1911 pistol during World War I. There were two variations of the M1917, one made by Colt and the other made by Smith & Wesson. They used moon-clips to hold the rimless cartridges in position and to aid in extraction. After World War I, they gained a strong following among civilian shooters. A commercial rimmed cartridge, the .45 Auto Rim, was also developed, that allowed them to be fired without the need for moon-clips.

Background

Smith & Wesson Model 1917 revolver

U.S. civilians arms companies of Colt and Remington-UMC 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. Both companies' revolvers utilized half-moon clips to extract the rimless .45 ACP cartridges. Daniel B. Wesson's son Joseph Wesson invented and patented the half-moon clip, which was assigned to Smith & Wesson, but at the request of the Army allowed Colt to also use the design free of charge in their own version of the M1917 revolver.

Smith & Wesson M1917 revolver

Smith & Wesson M1917 revolver

The Smith & Wesson Model 1917 was essentially an adaptation of that company's Second Model .44 Hand Ejector, chambered instead for .45 ACP, employing a shortened cylinder allowing for use of half-moon clips, and a lanyard ring on the butt of the frame. Smith & Wesson had until then (c. 1915–16) produced the Hand Ejector, which uses their heavy .44 caliber frame, for the British Army in .455 Webley caliber due to shortages in British production facilities of standard-issue Webley Mk VI top-break revolvers.

The S&W M1917 is distinguishable from the Colt M1917 in that the S&W cylinder had a shoulder machined into it to permit rimless .45 ACP cartridges to headspace on the case mouth (as with automatic pistols). The S&W M1917 could thus be used without the half-moon clips, though the empty cases would have to be poked-out manually through the cylinder face, since the extractor star cannot engage the rimless cases.

Colt M1917 revolver

Colt M1917 revolver

Colt had produced a revolver for the U.S. Army called the M1909, a version of their heavy-frame, .45-caliber, New Service model in .45 Long Colt to supplement and replace a range of 1890s-era .38 caliber Colt and Smith & Wesson revolvers that had demonstrated inadequate stopping power during the Philippine–American War. 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 could slip forward into the cylinder and away from the firing pin. Later production Colt M1917 revolvers had headspacing 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 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.

Later use

Full and half moon clips loaded with .45 ACP and one Truncated Cone .45 Auto Rim cartridge.

The military service of the M1917 did not end with the First World War. The M1917s saw action again during World War II, when it was issued to "specialty troops such as tankers and artillery personnel." During the Korean War they were again issued to support troops. The M1917s were even used by the "tunnel rats" during the Vietnam War.

The British Army adopted it during World War I, and the Home Guard and the Royal Navy used it during the Second World War.

The M1917 was also popular on the civilian and police market. Some were military surplus. Others were newly manufactured. Smith & Wesson kept their version in production for civilian and police sales until they replaced it with their Smith & Wesson Model 22 in 1950.

A .45 AUTO RIM cartridge (left) compared to a .45 ACP cartridge (right).

After the War, Naomi Alan, an engineer employed by Smith & Wesson, developed the 6-round full-moon clip. However, many civilian shooters disliked using moon clips. Although full moon clips allow a 1917 to be very quickly reloaded, loading and unloading the clips is tedious, and bent clips can bind the cylinder and cause misfires. For these reasons, in 1920, the Peters ammunition company introduced the .45 Auto Rim. This rimmed version of the .45 ACP allowed both versions of the Model 1917 revolver to fire reliably without the clips. In the late 1950s and 1960s, Colt and Smith & Wesson 1917s were available through mail order companies at bargain prices.

In 1937, Brazil ordered 25,000 Smith & Wesson M1917s for its military, where they are no longer in service.They can be identified by the large Brazilian crest stamped on their sideplates and are sometimes referred to as the M1937 or the Brazilian-contract M1917. They have altered rear sights, and most were fitted with commercial-style checkered grips, though some utilized smooth grips left over from the United States contract.

See also

• Colt New Service
• Smith & Wesson Triple Lock
• Service Pistol
• Smith & Wesson Model 10

Further reading

• Field Manual 23-35 Pistols and Revolvers, 26 February 1953
• Chamberlain & Taylerson, W.H.J. & A.W.F. (1989). Revolvers of the British Services, 1854-1954. Bloomfield, ON (Canada) and Alexandria Bay, N.Y. (USA): Museum Restoration Service. ISBN 0-919316-92-1. 
• Law, Clive M. (1994). Canadian Military Handguns, 1855-1985. Bloomfield, ON (Canada) and Alexandria Bay, N.Y. (USA): Museum Restoration Service. ISBN 0-88855-008-1. 
• Maze, Robert J. (2002). Howdah to High Power: A Century of Breechloading Service Pistols (1867-1967). Tucson, Ariz. (USA): Excalibur Publications. ISBN 1-880677-17-2. 
• Murphy, Bob (1985). Colt New Service Revolvers. Aledo, Illinois (USA): World-Wide Gun Report, Inc.. 
• Phillips & Klancher, Roger F. & Donald J. (1982). Arms & Accoutrements of the Mounted Police, 1873-1973. Bloomfield, ON (Canada) and Alexandria Bay, NY (USA): Museum Restoration Service. ISBN 0-919316-84-0. https://archive.org/details/armsaccoutrement0000phil. 
• Smith, W.H.B: "1943 Basic Manual of Military Small Arms" (Facsimile). Stackpole Books, Harrisburg, Pa. (USA), 1979. ISBN:0-8117-1699-6
• Speer Reloading Manual Number 3, Lewiston, Idaho, Speer Products Inc., 1959
• Taylor, Chuck: "The .45 Auto Rim," Guns Magazine, September 2000
• U.S. Army Ordnance Department (1919). Handbook of Ordnance Data. Washington: U.S. Government Printing Office. pp. 338–341. https://hdl.handle.net/2027/nyp.33433007163391?urlappend=%3Bseq=356. 
• Venturino, Mike " WWI Classic Returns", Guns Magazine December 2007, San Diego, Publishers Development Corp. 2007