ODIN Works AR10 Black Nitride Bolt Carrier Group BCG Black ACC-308 -BCG. Will work with .308 6.5 CM 6 CM and any other caliber using that size of case head. Smaller diameter firing pin and pin hole helps with high pressure cartridges. Specifications for ODIN Works AR10 Black Nitride Bolt Carrier Group (BCG): Manufacturer: ODIN Works Color: Black Finish: Nitride Fabric/Material: Steel Carrier Material: 8620 Steel Bolt Material: 9310 Steel Caliber: Universal Gun Model: AR-15 Condition: New Features of ODIN Works AR10 Black Nitride Bolt Carrier Group BCG: Carrier made from case hardened 8620 Black nitride finish (QPQ) Multi Caliber High Pressure bolt MPI and HPT tested Properly staked gas key made from 4130. Hardened 4340 cam pin Bolt made from case hardened 9310 Extractor 4340 steel made in specialized factories Fits DPMS style and other AR10 rifles Package Contents: ODIN Works AR10 Black Nitride Bolt Carrier Group What firearm models does the manufacturer say ODIN Works AR10 Black Nitride Bolt Carrier Group (BCG) is compatible with? The manufacturer suggests that ODIN Works AR10 Black Nitride Bolt Carrier Group (BCG) is compatible with AR-15The ODIN Works AR10 bolt carrier group is designed for multi caliber use. Will work with .308 6.5 CM 6 CM and any other caliber using that size of case head. Smaller diameter firing pin and pin hole helps with high pressure cartridges. Features/Specifications: Carrier made from case hardened 8620Black nitride finish (QPQ)Multi Caliber High Pressure boltMPI and HPT testedProperly staked gas key made from 4130.Hardened 4340 cam pinBolt made from case hardened 9310Extractor 4340 steelmade in specialized factoriesFits DPMS style and other AR10 rifles