DPMS AR-10 .308 Caliber Bolt Carrier Group Nitride Black. 308 Nitride Bolt Carrier Group. 9310 steel bolt assembly with extra strength extractor springs that is nitride for increased durability. 8620 carrier nitride treated with a nitride treated gas key properly staked with grade 8 fasteners. Specifications for DPMS AR-10 .308 Caliber Bolt Carrier Group: Manufacturer: DPMS Color: Black Finish: Nitride Carrier Material: 8620 Steel Bolt Material: 9310 Steel Caliber: .308 Winchester Gun Make: AR Platform Gun Model: AR-10 Package Contents: DPMS AR-10 .308 Caliber Bolt Carrier Group What firearm models does the manufacturer say DPMS AR-10 .308 Caliber Bolt Carrier Group is compatible with? The manufacturer says that DPMS AR-10 .308 Caliber Bolt Carrier Group is compatible with AR-10DPMS DP51655141280: Ar-10 .308 Caliber Bolt Carrier Group Nitride Black