M14 Polytech

The M14 rifle, officially the United States Rifle, Caliber 7.62 mm, M14, is an American select fire battle rifle chambered for the 7.62×51mm NATO cartridge. It became the standard-issue rifle for the U.S. military in 1957, replacing the M1 Garand rifle in service with the U.S. Army by 1958 and the U.S. Marine Corps by 1965; deliveries of service rifles to the U.S. Army began in 1959. The M14 was used by the U.S. Army, Navy, and Marine Corps for Basic and Advanced Individual Training from the mid-1960s to the early 1970s.[5][9]

The M14 was the last American battle rifle issued in quantity to U.S. military personnel. In 1967, it was officially replaced by the M16 assault rifle, a lighter weapon with a smaller 5.56x45mm intermediate cartridge. The M14 rifle remains in limited service across all branches of the U.S. military, with variants used as sniper and designated marksman rifles, accurized competition weapons, and ceremonial weapons by honor guards, color guards, drill teams, and ceremonial guards. Civilian semiautomatic variants are used for hunting, target shooting, and shooting competitions.[5]

The M14 served as the basis for the M21[10] and M25 sniper rifles, which were eventually replaced by the M24 Sniper Weapon System. A new variant of the M14, the Mk 14 Enhanced Battle Rifle, has been in service since 2002