PSA Logoed Premium 5.56 Nickel Boron BCG with Carpenter 158 Bolt - 516446450

Nickel boron coated full-auto profile bolt carrier group. Milspec Carpenter No. 158A(R) steel boltShot Peened BoltHigh pressure testedMag particle inspectedGas Key Hardened to USGI SpecificationsGas Key Grade 8 Hardened FastenersGas Key Staked Per Mil-SpecTool Steel ExtractorExtractor SpringExtractor O-ring InsertPSA LogoFor packaging considerations, BCG will be packed dry. Nickel Boron's natural surface lubricity is not a substitute for normal rifle lubrication. Please follow all manufacturers recommendations for lubrication. It is possible to discolor the finish with dirty ammo or prolonged use without cleaning.