Purchase the NBS True Mil-Spec SP/HPT/MPI 5.56 Bolt Carrier Group here!

Right here is a True Mil-Spec BCG. This unit is for builders who prefer tried and true manufacturing and aggressive quality assurance testing over fancy coatings, proprietary profiles and laser engraved logos.

Bolt

  • Machined from Carpenter Technology No. 158 alloy.
  • Heat treated
  • Shot peened per ASTM B851/SAE AMS2430S
  • Individually High Pressure Tested (test fired)
  • HP proof testing, 100% using a high pressure M197 or SAAMI commercial equivalent, without evidence of failure
  • Individually Magnetic Particle Inspected after Initial Test Fire
  • Manganese Phosphate Finish

Extractor

  • Tool Steel Extractor
  • Manganese Phosphate Finish
  • Mil-Spec O-Ring

Carrier

  • Machined from AISI 8620 aircraft quality alloy per ASTM A108/A322-13
  • Full Mass M16 Profile
  • Stress Relieved
  • Hard Chrome Bore

Gas Key

  • Machined from 4130 chromoly steel alloy per ASTM A108/A322-13
  • Grade 8 Hardware
  • Properly Staked
  • Hard Chrome Internal
  • Permatex sealed

Like all NBS parts, this unit is backed by a lifetime warranty.

Take a look at our other AR-15 Parts here!

Advertised price expires 07/10/2021