Adams Arms' P1 is the introductory model to the P-Series. This model features an ergonomic, mid-length Magpul MOE handguard and the standard adjustable Picatinny railed piston system. The P1 is perfect for any and all AR enthusiasts looking for a self-cleaning, piston driven upper that provides superior performance. The bolt carrier is full auto-rated, one-piece with an integral piston strike face. The 16" barrel has a government profile, A2 flash hider, and a QPQ melonite/black nitride finish. It has an optic ready, forged A4 flattop receiver, a 0.750" gas block diameter, and M4 feed ramps. This upper receiver weighs 4.46 lbs.