Bolt – Carpenter 158 heat-treated, shot peened and magnetic particle inspected. Manufactured to government drawings. Mil Spec gas rings. NiB-X Black coated (40% more wear-resistant than chrome).Extractor – Manufactured, heat treated, and hardened per government drawings. Black extractor buffer and heavy-duty spring. NiB-X Black coated. Firing Pin – Manufactured, heat-treated, hardened, chromed and certified per government drawings. Carrier – AR-15 or M16 style (heavy weight), 8620 material, heat treated and case hardened. Manufacturing tolerances on inside diameters tightly controlled. NiB-X Black coated for durability and ease of cleaning. Gas Key – Hardened to USGI Specifications and attached using grade 8 hardened fasteners. NiB-X Black coated. Staked per military specifications. Cam pin – Manufactured, heat treated, hardened and certified per Government drawings. NiB-X Black coated.