Palmetto State Armory

PSA 5.56 NITRIDE MPI FULL-AUTO BOLT CARRIER GROUP Bolt Finish: Nitride Bolt Steel: 9310 Profile: Full Auto Profile Gas Key: Grade 8 Hardened Fasteners, Staked per MilSpec Bolt is Magnetic Particle Inspected (MPI) **Due to part constraints, some orders may receive a free upgrade to a Mil-Spec Carpenter 158 Bolt**