Primary Weapons Systems Piston M13.5x1 LH Black

Primary Weapons Systems Piston M13.5x1 LH Black. Starting out by producing muzzle devices they tested their compensators on all different types of rifles - from M4s to AK-47s. After using both styles of rifles in testing with high round counts the difference in maintenance needed was both astounding. From that basic realization the PWS long-stroke piston system was born; keeping the core values of the AR-15 design while also lessening the need for maintenance in high-volume fire situations and a