Abstract: A gasket designed to fit into the bottom of the lower receiver of an M16 and AR style rifle. The gasket assists in preventing debris and blown primers from inhibiting the firing motion of the trigger of the rifle. The gasket surrounds a portion of the trigger within the lower receiver without impeding the movement of the trigger. The gasket lies flat in the bottom of the lower receiver and is retained in place by the installed trigger and trigger spring.

Abstract: A gun barrel handguard includes half sections having longitudinally spaced apart fins of plastic material positioned around the exterior of the gun barrel for absorbing heat but preventing it from being quickly transmitted to the exterior of the handguard.

Abstract: A receiver block particularly configured for an AR-15/M-16 receiver includes an upwardly extending tongue adapted to be received in the receiver cavity with oppositely positioned ears on the receiver being received in apertured slots on the receiver block with pins being received in the aligned openings to lock the receiver to the receiver block thereby providing substantially total exposure and access to the receiver.

Abstract: Rifle front and rear flip up sights include a base member attached to the gun with a sight arm pivotally attached to the base member and being biased pivotally downwardly from one end of the base member while a support member is biased pivotally upwardly from the opposite end with the free ends of each engaging each other in a locked condition when both are in their raised positions. The sight arm allows the support arm to be pivoted downwardly under the sight arm with the downward bias of the sight arm holding the sight assembly in a locked lowered position.

Abstract: An interchangeable upper receiver assembly for use with a hand held weapon and the interchangeable upper receiver assembly in combination with the hand held weapon, where the interchangeable upper receiver assembly includes an integral, unitary breech block and barrel that is operably removably couplable to the lower receiver assembly of the hand held weapon in an engaged disposition. A bolt assembly is slidably disposed within a bolt recess defined in the receiver breech block and barrel. The bolt includes a firing pin slidably disposed therein, the firing pin being selectively actuatable by the trigger assembly when the receiver is in the engaged disposition.