White Label Armory AR-15 Carbine Buffer Tube 6 Position Mil-Spec

The receiver extension is what everything behind the AR-15 lower hangs on, and this one is cut to mil-spec dimensions so standard carbine stocks and pistol braces slide on without slop. Six positions of length adjustment, aluminum construction, and a slick coating so the stock slides without grinding.

It weighs 3.8 oz. This is the tube on its own — buffer, recoil spring, castle nut and end plate are all separate purchases. Mil-spec diameter also means commercial diameter stocks will not fit, so check what is already in the parts bin before ordering.