The M14 rifle firearm is based off the very successful M1 Garand which was used in WWII. Even with the success of the M1 Garand, it had its flaws, thus the M14 was born. Using the 7.62 (.308) round, and the ability of automatic fire, the M14 was a champion design. Used primarily in the Vietnam war. Although the M14 was phased out as the standard-issue rifle in the sixties by the M16, the M14 has fought back in many modern military units.