|Barrel:||22 in (559 mm)|
|Region of Origin:||United States|
|Cartridge:||7.62×51mm NATO (.308 Winchester)|
460 m (500 yd)
|Rate of Fire:||700–750 rounds/min|
M14 rifle, formally the United States Rifle, 7.62 mm, M14, is an American selective fire automatic rifle firing 7.62×51mm NATO (.308 Winchester) ammunition. It was the standard issue U.S. rifle from 1959 to 1970.
The M14 rifle was used for U.S. Army and Marine Corps basic and advanced individual training, and was the standard issue infantry rifle for U.S. military personnel in the Contiguous United States, Europe, and South Korea, until it was replaced by the M16 rifle, in 1970. The M14 rifle remains in limited front line service within all branches of the U.S. military, and is also used as a ceremonial weapon by honor guards, color guards, drill teams, ceremonial guards, and the like.
The M14 rifle was also the last American "battle rifle" (a term applied to weapons firing full-power rifle ammunition, such as the 7.62mm cartridge) issued in quantity to U.S. military personnel. The M14 rifle also provides the basis for the M21 and M25 sniper rifles.
The M14 was developed from a long line of experimental weapons based upon the M1 rifle. Although the M1 was among the most advanced infantry rifles of the late 1930s, it was not a perfect weapon. Modifications were beginning to be made to the basic M1 rifle's design since the twilight of World War II. Changes included adding fully automatic firing capability and replacing the 8-round en bloc clips with a detachable box magazine holding 20 rounds. Winchester, Remington, and Springfield Armory's own John Garand offered different conversions. Garand's design, the T20, was the most popular, and T20 prototypes served as the basis for a number of Springfield test rifles from 1945 through the early 1950s. T25 prototype
In 1945, Earle Harvey of Springfield Armory designed a completely different rifle, the T25, for the new T65 .30 Light Rifle cartridge at the direction of Col. Rene Studler, then serving in the Pentagon. In late 1945 the two men were transferred to Springfield Armory, where work on the T25 continued. The T-25 was designed to use the T65 service cartridge, a Frankford Arsenal design based upon .30-06 cartridge case used in the M1 service rifle, but shortened to the length of the .300 Savage case. Although shorter than the .30-06, with less powder capacity, the T65 cartridge retained the ballistics and energy of the .30-06 due to the use of a recently developed ball powder made by Olin Industries. After experimenting with several bullet designs, the T65 was finalized for adoption as the 7.62x51mm NATO cartridge. Olin Industries later marketed the cartridge on the commercial market as the commercial .308 Winchester round. After a series of revisions by Earle Harvey and other members of the .30 Light Rifle design group following the 1950 Ft. Benning tests, the T25 was renamed the T47.
In contrast, the T44 prototype service rifle was not principally designed by any single engineer at Springfield Armory, but rather was a conventional design developed on a shoestring budget as an alternative to the T47. With only minimal funds available, the earliest T44 prototypes simply used T20E2 receivers fitted with magazine filler blocks and re-barreled for 7.62mm NATO, with the long operating rod/piston of the M1 replaced by the T47's gas cut-off system. Lloyd Corbett, an engineer in Earle Harvey's rifle design group, added various refinements to the T44 design, including a straight operating rod and a bolt roller to reduce friction.