Spikes Tactical ST5BG01 Bolt Carrier Group M16 .223/5.56 NATO Steel Black Phosphate

Spikes Tactical ST5BG01: The Spike's Tactical HPT/MPI M16 Bolt Carrier Group for .223/5.56 NATO features a Mil-Spec 8620 tool steel M16 bolt carrier w/shrouded firing pin. The carrier has 5.3.1.2 MIL-STD-171 phosphate finish inside and out with 1.2.2.2 MIL-STD-171 hard chrome bore. It is laser-engraved with ST Spider logo which is visable through ejection port door opening. The carrier key is attached with Grade 8 hardware and properly staked per the Mil-Spec. The bolts are CNC machined from Carpenter No. 158 and have 5.3.1.2 MIL-STD-171 phosphate finish inside and out. All bolts are shot peened per the current Mil-Spec and individually High Pressure Tested (HPT) and then Individually Magnetic Particle Inspected (MPI). The tool steel extractor is shot peened, has a 5.3.1.2 MIL-STD-171 phosphate finish, and is fitted with a Mil-Spec black extractor spring insert and Mil-Spec Viton o-ring. The Mil-Spec firing pin has a 1.2.2.2 MIL-STD-171 hard chrome finish. The Mil-Spec cam pin also has a 5.3.1.2 MIL-STD-171 phosphate finish. The Mil-Spec firing pin retaining pin has a 5.3.1.2 MIL-STD-171 phosphate finish.