US Patent 8464457 Firearm handguard system

A clamping mechanism for attaching a handguard to a firearm includes a barrel nut having radially outwardly directed tines, a tubular body having a plurality of longitudinal grooves separated by lands forming an inner surface of the tubular body, and a pair of circumferentially extending grooves traversing the lands, formed forward from a rearward end of the tubular body. A clamp element is carried by the tubular body and includes a body with a beveled end and a heel extending substantially perpendicularly from an opposing end of the body. The clamp element is adjustably positioned within the tubular body with the heel extending radially outwardly and received in the second groove and the beveled end engages the barrel nut.