• Carpenter 158 steel — the mil-spec bolt material
  • Heat-treated and shot-peened for fatigue resistance
  • MPI (magnetic particle) tested to detect any surface or subsurface flaws
  • Nickel boron coating on the bolt body and extractor for corrosion resistance
  • Relief-cut cam pin channel to reduce bolt-lug stress

Full details and secure checkout: https://3crtactical.com/223-5-56-300blk-nickel-boron-bolt-carrier-group-69057/?utm_source=armslist&utm_medium=referral&utm_campaign=listing