Addax Tactical ATAC (Advanced Tactical AR Carbine) GPU
The Addax ATAC (Advanced Tactical AR Carbine) GPU (Gas Piston Upper) from Addax Tactical is a new gas piston AR upper that utilizes a long stroke piston system, with the piston attached to the bolt carrier rather than the short stroke piston of the earlier PWS system. This was originally developed for the shorty 7″ Diablo upper by Primary Weapon Systems (PWS) but is also available for longer barrels.