Description
AO Precision C158 SP/HPT/MPI 5.56 Black Nitride Bolt Carrier GroupAO Precision has provided BCGs to large military contractors such as FN America and large commercial retailers who re-brand and sell these at a considerable mark-up.BoltMachined fromCarpenter Technology No. 158 alloy.Heat treatedShot peenedper ASTM B851/SAE AMS2430SIndividually High Pressure Tested (test fired)HP proof testing,100%using a high pressure M197 or SAAMI commercial equivalent, without evidence of failureIndividually Magnetic Particle Inspected after Initial Test FireBlack Nitride FinishExtractor4140 Steel per ASTM A108, cold drawn and stress relieved BHN 187-22Phosphate FinishExtractor SpringBlack Extractor InsertViton O-RingCarrierMachined from AISI 8620 aircraft quality alloy per ASTM A108/A322-13Full Mass M16 ProfileStress RelievedBlack Nitride FinishGas KeyMachined from 4130 chromoly steel alloy per ASTM A108/A322-13Grade 8 HardwareProperly StakedHard Chrome InternalPermatex sealed
