Faxon Firearms .308 / 6.5 Creedmoor / 8.6 BLK Bolt Carrier Complete 9310 Tool Steel Nitride Gen 2 Black. Improvements include using 9310 tool steel for the bolt nitriding the assembly to increase surface hardness decrease resistance and have superior corrosion resistance compared to typical chrome and phosphasted bolt carrier groups. All bolts are fully MPI tested to ensure the material is sound and without defects. Bolt lugs are chamfered 45 degrees to ensure reliable action for even the highest pressure hand loads and fast lightweight actions. Faxon Bolt Carrier Groups are Superfinished to reduce friction increase smoothness of operation and reduce fouling. Further they are full-Auto rated and maintain the trip for full-auto fire control groups and new multi-stage trigger systems. Gas keys use grade 8 fasteners and are fully staked for a lifetime of service. Detailed Specifications: 9310 Tool Steel Bolt Full MIL-SPEC Heat Treatment Shot Peened to MIL-SPEC Magnetic Particle Inspection (MPI) Back of Lugs Chamfered for Reliability 308 Spec Springs & Dual O-Ring Installed Salt Bath Nitrided Bolt & Carrier S7 Extractor Superfinished Carrier Body Specifications for Faxon Firearms .308 9310 Bolt Carrier Complete: Manufacturer: Faxon Firearms Color: Black Finish: Nitride Fabric/Material: 9310 Tool Steel Carrier Material: 8620 Steel Bolt Material: 9310 Steel Caliber: 6.5mm Creedmoor .308 Winchester Gun Make: AR Platform Gun Model: DPMS LR-308 AR-10 Condition: New Features of Faxon Firearms .308 9310 Bolt Carrier Complete - Nitride Bolt: 9310 Tool Steel Construction (Stronger than C158); Full MIL-SPEC Heat Treatment; Shot Peened to MIL-SPEC; Back of Lugs Chamfered for Reliability; Nested .308 Spec Springs with O-Ring Extractor: 4140 Tool Steel Construction; Fully Heat Treated; Shot Peened Per MIL-SPEC Carrier & Key: Superfinished Carrier; Carrier: MIL-SPEC 8620 Steel Material; Key: 4140 Steel Material; Fully Heat Treated; Forward Assist Serrations; Grade 8 Fasteners; Fully & Properly Staked Key; Cam Pin: 4140 Pre-Hardened Steel Material Note - Bolt carriers ordered and deployed with barrels not specifically checked by Faxon for headspacing MUST be checked to ensure safe and reliable function. Faxon recommends Pacific Tool & Gauge headspace kits for all measurements. Package Contents: Faxon Firearms .308 9310 Bolt Carrier Complete - Nitride What firearm models does the manufacturer say Faxon Firearms .308 9310 Bolt Carrier Complete is compatible with? The manufacturer suggests that Faxon Firearms .308 9310 Bolt Carrier Complete is compatible with AR-10 DPMS LR-308Faxon Firearms FF308BCGCNITRIDE-02: .308 / 6.5 Creedmoor / 8.6 BLK Bolt Carrier Complete 9310 Tool Steel Nitride Gen 2 Black