during 1967. Stoner 63/63A Light Machine Gun: The LMG configuration fires from an open bolt and is fed from the right-hand side by linked ammunition contained in a 75, 100, 150-round drum magazine. The receiver is identical to the Rifle variants, but is inverted, so that spent cases and links are ejected to the left. The LMG has a quick-change barrel and the gas cylinder is positioned below the barrel since the receiver is inverted. The LMG configuration was adopted for military use by Navy SEAL units operating in Southeast Asia. Stoner 63/63A Medium Machine Gun: Identical to the LMG configuration. The difference is that the MMG comes with a separate adapter than can be used to attach the weapon to an M2 or M122 tripod. Stoner 63/63A Fixed Machine Gun: Internally identical to the LMG configuration. Externally, the front sights, rear sights, foregrip and pistol grip are all removed. The trigger is activated remotely by a 24V solenoid. The FMG was designed for use with the Cadillac Gage Commando APC, but was never officially adopted. Stoner 63/63A Commando: The Commando is a derivative of the LMG configuration. It is fed from the right by a 100-round drum magazine clipped below the receiver. The cocking handle is mounted underneath the foregrip for easier access. To save weight, the Commando eschews the quick-change barrel found on the other belt-fed configurations. This variant was used by some United States Navy SEAL units in Vietnam. Stoner 63 Survival Rifle: The Survival Rifle was designed in 1964 to compete with the Colt Model 608 as an aircrew self-defense weapon. It is mechanically similar to the Rifle configuration, but has several external modifications made to fit into United States Air Force size constraints. These include a cut-down pistol grip, an absent handguard, shortened barrel and receiver, and a top-mounted cocking handle. The Survival Rifle does not incorporate the 63A upgrades. Only one prototype was ever produced—it survives to this day. Stoner 66 Civilian Rifle: A short-lived semi-automatic version for the civilian market. Never actually allowed to be sold. The most recent descendant of this line is the Stoner LMG produced by Knight's Armament Company, which has significant changes from the older Stoner 63, being based on Stoner's later model 86. Robinson Armament Co. also produced the semi-automatic M96 Expeditionary Weapon System which, though technically different, was based on the Stoner 63 design, and thus has