Patent ID: 8210089

Claim:
A firearm comprising: a barrel defining a first bore extending along a longitudinal axis and having a breech and a muzzle defining a length of said barrel; a hand guard defining a second bore extending substantially parallel to said longitudinal axis and having a first end coupled to said breech and a second end spaced from said first end along said longitudinal axis toward said muzzle; a housing coupled to said second end of said hand guard and defining a chamber extending along a piston axis; a piston disposed within said chamber of said housing and movable along said piston axis between a static position and a displaced position; a receiver coupled to said first end of said hand guard and said breech of said barrel with said receiver defining a third bore extending substantially parallel to said longitudinal axis; a bolt carrier disposed in said third bore of said receiver and moveable relative to said receiver along said longitudinal axis between a firing position and a rearward position; a carrier key attached to said bolt carrier and moving concurrently with said bolt carrier between said firing and rearward positions with said carrier key extending outwardly above said bolt carrier and along said piston axis; and a rod permanently affixed to said carrier key and extending along said piston axis to a distal end with said piston adjacent said distal end when in said static position and said piston engaging said distal end when moving to said displaced position for moving said bolt carrier from said firing position to said rearward position.