ODIN Works 6.5 Grendel Type 2 Black Nitride Bolt Carrier Group BCG Black Type-2 6.5 Grendel ACC-6.5- BCG. 5 Grendel Type 2 bolt face - Black Nitride Bolt Carrier Group BCG Specifications for ODIN Works Nitride Bolt Carrier Group (BCG) Black: Manufacturer: ODIN Works Color: Black Finish: Nitride Fabric/Material: Steel Carrier Material: 8620 Steel Bolt Material: 9310 Steel Caliber: 6.5mm Grendel Gun Model: AR-15 Condition: New Features of ODIN Works Nitride Bolt Carrier Group BCG Black: Type 2 6.5 Grendel bolt face. True Mil-Spec Bolt Carrier Group BCG Material: Case Hardened 8620 Steel Finish: Black Nitride This advanced low friction coating minimizes the need for lubricants. Gas Key: 4130 Steel attached with Grade 8 hardware and properly staked into a milled valley to ensure proper positioning. Cam Pin: Hardened 4340 cam pin Firing Pin: Mil Spec firing pin made of 8740 steel center-less ground and Hard Chrome coated Bolt Assembly: The Bolt is true Mil Spec dimension and external surfaces are CNC ground after heat treat for a precision fit. Bolt Material: Case Hardened 9310 Steel. Finish: All Bolt components Shot Peened and Manganese Phosphate or Black Nitride Extractor: 4340 Steel Manganese Phosphate coated Mil Spec Extractor Spring O-Ring Combination MPI: Magnetic Particle Inspected HPT: High Pressure Test Package Contents: ODIN Works Nitride Bolt Carrier Group Black What firearm models does the manufacturer say ODIN Works Nitride Bolt Carrier Group (BCG) Black is compatible with? The manufacturer says that ODIN Works Nitride Bolt Carrier Group (BCG) Black is compatible with AR-156.5 Grendel Type 2 bolt face - Black Nitride Bolt Carrier Group Features/Specifications: Type 2 6.5 Grendel bolt face.True Mil-Spec Bolt Carrier GroupMaterial: Case Hardened 8620 SteelFinish: Black Nitride. This advanced low friction coating minimizes the need for lubricants.Gas Key: 4130 Steel attached with Grade 8 hardware and properly staked into a milled valley to ensure proper positioning.Cam Pin: Hardened 4340 cam pinFiring Pin: Mil Spec firing pin made of 8740 steel center-less ground and Hard Chrome coatedBolt Assembly: The Bolt is true Mil Spec dimension and external surfaces are CNC ground after heat treat for a precision fit.Bolt Material: Case Hardened 9310 Steel.Finish: All Bolt components Shot Peened and Manganese Phosphate or Black NitrideExtractor: 4340 Steel Manganese Phosphate coatedMil Spec Extractor Spring O-Ring CombinationMPI: Magnetic Particle InspectedHPT: High Pressure Test