Stoners!

A somewhat obscure weapon from the Vietnam War Era. The Stoner 63 was an attempt by Eugene Stoner and Cadillac Gage to give the military an easy to produce all in one weapon system that can switch from an assault rifle, to a light machine-gun, and an automatic rifle. Though it was more high maintenance and the Army and Marines passed on it, the weapon found a home with the Navy Seals and served as their standard light machine gun till they adopted the FN-Minimi/M249 in the 1980s.