Active from 1977 to 2007, Rock Island Armory chiefly dealt in military surplus but was also known for producing mil-spec receivers. Owned by the same family as the similarly-named Springfield Armory Incorporated, there was a lot of overlap between the output of the two firms including the SA-1; built around a semi-automatic closed bolt receiver, the SA-1 is a very close, yet civilian legal, copy of the U.S. Army's M60 light machine gun. Blade front and folding adjustable notch rear sights with a birdcage flash hider, folding bipod and gas regulator mounted to the quick detachable barrel. The receiver is marked "RIA GENESEO/IL SA1 M60 18" on the left side with a bolt hold-open lever and two position selector. Included with the rifle is a green canvas sling, plastic hard case, plastic ammo bin with canvas cover marked "LAX/JUN 1970", metal ammunition tin full of disintegrating belt links, and a quick-detach forearm mounting bracket.