Abstract: A lower sling attachment adapter for use in the M-16 rifle and M-4 carbine and their equivalents utilizing a rear or butt stock mounted on a tube, one end of which tube is threaded into the rear of the receiver of the weapon, the improvement comprising a lower sling attachment means mounted on said threaded tube near the receiver and having a hole through which the said threaded end of said tube is passed, said lower sling attachment means having sling mount means on at least one side thereof to which the lower end of a weapon sling is attached.