Early M1A receivers were made from surplus M14 receiver blanks, current M1A receivers are made from precision investment cast AISI 8620 alloy steel. The military M14 receivers were manufactured using the drop forge process, which is more complicated and more expensive. Until around the late 1990s, the M1A produced by Springfield Armory retained the cutout in the rear right of the stock for the selector switch found on the M14. Springfield Armory has also omitted the "7.62-MM" caliber designator on the M1A receiver since 1991.