Complete 6.5 Creedmoor Bolt Carrier Group Mk3/LR-308 platform. Features high-pressure design to reduce primer cratering with high-pressure loads. – Bolt: 9310 Steel Phosphate Finish high-pressure design – Carrier: 8620 Steel Chrome Lined Phosphate Finish – Extractor: S7 Tool Steel Phosphate Finish – Firing Pin: 17-4 Stainless Steel high-pressure design