BattleHawk Armory Complete M16 AR-15 5.56/300 Black Chrome Phosphate Bolt Carrier Group Experience the ultimate in precision engineering with the BattleHawk Armory Complete Bolt Carrier Group, built to exceed Mil-Spec standards. Crafted from Mil-Spec 8620 steel and finished with a manganese phosphate coating, this BCG offers long-lasting corrosion resistance and a rugged exterior. Inside, a hard chrome-lined surface creates a mirror-like, near friction-less finish that seasoned shooters and experienced builders rely on for tens of thousands of rounds. Our Secret Sauce: This BattleHawk BCG is precision ground-both the outside and all three interior dimensions are meticulously machined and ground to deliver the smoothest possible operating surface. Key Components: M16 Style Carrier: Machined from 8620 Steel Chrome-Lined Heat Treated Final Grind Before Plating Manganese Phosphate Finish 5.56/.223 Bolt: Machined from Carpenter 158A(R) (9310 Steel) Heat Treated and Shot Peened MPI Tested (Magnetic Particle Inspection) Phosphate Finish Billet Gas Key: Machined from a Solid Billet of 4130 Steel Chrome-Lined Secured with Grade 8 Fasteners and Properly Staked Manganese Phosphate Finish Cam Pin: Machined from 4140 Steel Heat Treated Manganese Phosphate Finish Billet Extractor: Machined from a Solid Billet of 4140 Steel Heat Treated and Shot Peened Phosphate Coated Includes Extractor Insert and Viton O-Ring Firing Pin: Machined from 8640 Steel Hard Chrome Plated 100% American Made Lifetime Warranty: All BattleHawk Armory Precision Parts come with our Lifetime BATTLE.FOREVER Warranty, providing complete peace of mind and confidence in your purchase. Upgrade your AR-15 with this best-in-class BCG, engineered to deliver exceptional reliability and performance round after round. At BattleHawk Armory, we team up with only the best manufacturers in the industry and offer amazing products to our precision engineering specs with a Battle.Forever Lifetime Warranty!