Until the introduction of the M-16, the M-14 was the standard rifle of the US forces and saw service in Vietnam from 1957 onwards until its replacement. The M14 national Match (Accursed) was the sniper rifle variant, later renamed the M-21.
Production of the M14 ceased in 1964 but a further variant was the M14A1 which came close to being a light machine-gun. The M14A1 had a pistol grip, a folding fore-hand grip about half-way down the forestock, a folding bipod, a shoulder strap, and a sleeve was fitted over the muzzle to act as a compensator when firing fully automatic. This helped to keep the barrel down and prevent climb.
The M-14 was adopted in 1957 as the successor to the WWII M-1 Garand, and was basically an evolution of that rifle.
The main and more obvious improvements were the gas system and magazines. On the M-1 the magazine was fixed and had to be loaded using a charger. On the M-14, detachable 20-round box magazines were used. The normal M-14 fired semi-automatic only. A slide-on bipod could be provided, and the rifle fitted the M-76 grenade launcher which was slipped on to the flash suppressor and secured to the bayonet lug.
The M-14 weighed 5.1-kg (11.22 pounds) with a full magazine and cleaning kit carried. It had a maximum effective range on semi-automatic without the M-2 bipod of 460-meters. When the bipod was added this range increased to 700-meters.
A special suppressor was fitted to the muzzle of the sniper rifle which did not affect the performance of the bullet, but reduced the velocity of the emerging gases to below that of sound. This made location very difficult as the target heard only the crack of the bullet and no shot from the rifle.