5.56/300 AAC Blackout Melonite BCG
Mil-Spec MIL-STD-Phosphate Finish
Individually MPI Tested
9310 MPI tested Bolt
Carrier: 8620 Tool Steel-(M16 full shroud)-Heat Treated, Case Hardened, & Chrome Lined.
Gas Key: Tool Steel-Attached using Grade 8 Hardened Fasteners, & Staked.
Cam Pin: 4140 Steel
Extractor:Tool steel-shot peened
7.62x39 Chrome-Lined Bolt Carrier Group
Mil-Spec MIL-STD-Phosphate Finish
Individually MPI Tested
9310 MPI tested Bolt
Carrier: 8620 Tool Steel-(M16 full shroud)-Heat Treated, Case Hardened, & Chrome Lined.
Gas Key: Tool Steel-Attached using Grade 8 Hardened Fasteners, & Staked.
Cam Pin: 4140 Steel
Extractor:Tool steel-shot peened