The M14 rifle, officially the United States Rifle, Caliber 7.62 mm, M14, is an American selective-fire battle rifle chambered for the 7.62×51mm NATO (.308 in) 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. 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. 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, 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, plinking, target shooting, and shooting competitions. The M14 served as the basis for the M21 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. History Early development The M14's development stemmed from an extensive line of experimental weapons based on the M1 Garand rifle. Although the M1 was among the most advanced infantry rifle designs of the late 1930s, it was not without faults, as various modifications to the basic M1 were considered during the last months of World War II. Changes included the addition of fully automatic fire and the replacement of the eight-round en bloc clip with a detachable box magazine holding 20 rounds. Winchester, Remington, and Springfield Armory's John Garand offered alternate conversions. Garand's design, the T20, was the most popular, and T20 prototypes served as the basis for several Springfield test rifles from 1945 through the early 1950s. In 1945, Earle Harvey of Springfield Armory designed an entirely different rifle, the T25, for the new T65 .30 light rifle cartridge (7.62×49mm). This was at the direction of Col. Rene Studler, then serving in the Pentagon. Harvey and Studler were then transferred to Springfield Armory in late 1945, to continuously develop the T25. The T25 was designed to use the T65 service cartridge, a Frankford Arsenal design based upon the .30-06 cartridge