Brownells | 5.56x45 Bolt Carrier Group NiB



The Brownells M16 5.56 Complete Bolt Carrier Group features a bolt fabricated from 9310 steel that includes a heat-treated and shot-peened finish. The bolt carrier itself is built using 8620 steel, which features a hardened finish. The whole BCG is completed with a nickel-boron coating.



  • Steel quality assured with magnetic particle inspection
  • Features extractor with rubber insert and spring
  • Gas-key screws are torqued and staked
  • Designed for use with all 5.56-NATO-based cartridge cases.