M14 rifle, officially the United States Rifle, 7.62 mm, M14, is an American selective fire automatic rifle that fires 7.62×51mm NATO (.308 Winchester) ammunition. It gradually replaced the M1 Garand in U.S. Army service by 1961 and in U.S. Marine Corps service by 1965. It was the standard issue infantry rifle for U.S. military personnel in the contiguous United States, Europe, and South Korea from 1959 until it was replaced by the M16 rifle in 1970. The M14 was used for U.S.