M21 Report by Jester

The M21 is a National Match semi-automatic M14 rifle pressed into service as a sniper rifle. It is chambered 7.62x51mm NATO (.308 win) round, fired from detachable 20- or 5-round magazine. Earlier versions of the weapon (XM21) had a walnut stock, but this was changed to a fiberglass stock in the M21. The XM21 entered service in the U.S. Army in 1969 and remained the primary sniper rifle until it began to be replaced by the M24 in 1988.

The M21 was developed into the M25 by the 10th Special Forces Group, in conjuction with the Navy SEALs to fill the continuing need for a semi-automatic sniper rifle for some missions.