Mil-Spec M16 Bolt Carrier Group (BCG)

AO Precision Mil-Spec M16 Bolt Carrier Group (BCG)The AO Precision AR 15 Bolt Carrier Group is a true Mil-Spec BCG. The Bolt is manufactured from 158 carpenters steel and features a Manganese Phosphate Finish. Not only is each bolt carrier MPI inspected they also are individually test fired for quality assurance and reliability. Remember that Black Rifle Depot is your online shop for all of your AR 15 replacement parts, spare AR 15 parts, AR 15 upgrades, and other high quality AR 15 Parts because everyone wants a place to score cheap AR 15 parts.BoltMachined from Carpenter Technology No. 158 alloy.Heat treatedShot peened per 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 FireManganese Phosphate FinishExtractor4140 Steel per ASTM A108, cold drawn and stress relieved BHN 187-22Manganese Phosphate FinishExtractor SpringBlack Extractor InsertViton O-RingCarrierMachined from AISI 8620 aircraft quality alloy per ASTM A108/A322-13Full Mass M16 ProfileStress RelievedHard Chrome BoreGas KeyMachined from 4130 chromoly steel alloy per ASTM A108/A322-13Grade 8 HardwareProperly StakedHard Chrome InternalPermatex sealed