NBS AR-15 9310 Bolt Assembly - Black Nitride

Made from 9310 Steel which has a high core hardness and high fatigue strength unlike standard Hot/cold rolled 9310 steels. This is a Mil-Spec bolt assembly with enhanced features for those looking to complete a bolt carrier group. This bolt will make sure your gun outshines the competition - Fully Assembled 5.56/.223 Caliber Bolt - Shot Peened - MPI (Magnetic Particle Inspected) - HPT (High Pressure Tested) - Power Spring Kit - Nitride QPQ Treated - MPI/9310 ENGRAVINGS WILL VARY BY BATCH