These are New High Quality Spike's Tactical Bolt Carrier Groups with the Spike’s Spider Logo Laser engraved on the side.
Spike’s Tactical HPT/MPI M16 Bolt Carrier Group (223/5.56).Bolt carrier group specifications-
-Mil-Spec 8620 tool steel M16 bolt carrier w/shrouded firing pin.
-Carrier has 220.127.116.11 MIL-STD-171 phosphate finish inside and out with 18.104.22.168 MIL-STD-171 hard chrome bore.
-Laser engraved with ST Spider logo (visable through ejection port door opening).
-Mil-Spec tool steel carrier key.
-Carrier key has 22.214.171.124 MIL-STD-171 phosphate finish inside and out with 126.96.36.199 MIL-STD-171 hard chrome bore.
-Carrier key is attached with Grade 8 hardware and properly staked per the Mil-Spec.
-Bolts are CNC machined from Carpenter No. 158®.
-Bolts have 188.8.131.52 MIL-STD-171 phosphate finish inside and out.
-All bolts are shot peened per the current Mil-Spec.
-All bolts are Individually High Pressure Tested (HPT) and then Individually Magnetic Particle Inspected (MPI)
-Tool steel extractor, shot peened, 184.108.40.206 MIL-STD-171 phosphate finish, fitted with a Mil-Spec black extractor spring insert and Mil-Spec Viton o-ring.
-Mil-Spec firing pin with 220.127.116.11 MIL-STD-171 hard chrome finish.
-Mil-Spec cam pin with 18.104.22.168 MIL-STD-171 phosphate finish.
-Mil-Spec firing pin retaining pin with 22.214.171.124 MIL-STD-171 phosphate finish.