Description
The F-1 Firearms DuraBolt Black Nitride direct impingement full auto rated M16/M4 bolt carrier group, for use in AR15 platforms, is compatible with MIL-SPEC receivers and associated components. The bolt carrier and bolt are ground after heat treat to ensure tolerances.
- Carpenter 158 bolt, ground after heat treat, MPI and HPT
- 8620 steel carrier, ground after heat treat
