F1 Firearms 5.56mm NATO DuraBolt Bolt Carrier Group - Blue PVD - Blue

F1 Firearms 5.56mm NATO DuraBolt Bolt Carrier Group - Blue PVD - The F-1 Firearms DuraBolt Blue 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 DuraBolt Gold is enhanced with a Physical Vapor Deposition (PVD) TiN coating, which gives it an extremely durable and corrosion resistant gold mirror finish. The DuraBolt Golds coating also offers excellent lubricity with a 0.45 coefficient of friction. Carpenter 158 bolt, ground after heat treat, MPI and HPT and 9310 steel carrier, ground after heat treat.