Patent ID: 7793452

Claim:
A modular fore-end rail assembly for a firearm, said firearm including at least an upper receiver having a forward end and a rearward end, said upper receiver having a barrel receiving receptacle at said forward end thereof, said firearm further including a barrel received in said barrel receiving receptacle and a barrel nut received around an outer surface of said barrel receiving receptacle to retain said barrel within said barrel receiving receptacle, said modular fore-end rail assembly comprising: an upper handguard having a forward end and a rearward end, a dovetail rail extending longitudinally between the forward end and the rearward end, and opposing side walls that extend outwardly and downwardly from said dovetail rail, respectively, said opposing side walls terminating in mounting channels, said rearward end of said upper handguard including a first clamping member; a clamp removably secured to said rearward end of said upper handguard wherein said clamp cooperates with said first clamping member to engage said barrel nut, said clamp having an exterior surface including a slidable locking pin movable between a fixed locked position and a fixed unlocked position; and a lower handguard including side walls that extend outwardly and upwardly, said side walls terminating in mating formations that are configured to be slidably received in said mounting channels in said upper handguard and a lock aperture at a rearward end thereof, wherein said locking pin may be slidably engaged with said lock aperture to selectively retain said lower handguard with said upper handguard, said locking pin includes a surface defining slot interconnecting a pair of recessed surface defining holes configured and arranged to cooperate with a spring-biased retaining pin contained in said clamp to selectively hold said locking pin in said locked position and said unlocked position.