m14
The M14 is an American-designed 7.62×51mm NATO battle rifle, developed in 1954 by Earle Harvey and Lloyd Corbett at Springfield Armory, adopted by the U.S. military in 1959. Its design was heavily based on the earlier M1 Garand, but with the 20-round detachable magazines and ability to fire in full-automatic akin to the M1918 BAR instead of an 8-round internal magazine like the Garand.
Beginning in 1963, however, the M14 began to be supplanted by the M16 rifle, which fully replaced the M14 as the U.S military's main firearm by 1969. The M14 continues to be used in some secondary (marksman) and specialist roles due to its firepower, longer range and accuracy.