Tacfire .308 Bolt Carrier Group BCG for AR-10 pattern rifles. Serrated for use with a forward assist. 8620 steel carrier and 9310 steel bolt. Finish: QPQ Nitride. Caliber: .308 Winchester. Gun Model: AR-10. Condition: New. Magnetic Particle Inspected, Shot Peened, Nitride Treated Gas Key and Extractor, Staked Gas Key. Package Contents: Tacfire .308 Bolt Carrier Group. Compatible with DPMS LR-308 pattern AR rifles. Country of Origin: USA.