• Protected by NiB-X Nickel Boron underneath with TIN topcoat
  • NiB-X coated - 40% more wear-resistant than chrome, and can be used in the field without lubrication and are easily wiped clean
  • Over 30K rounds in Government protocol endurance testing did not wear the NiB-X coating off
  • Polished carrier to reduce fouling adherence
  • Heat-treated, shot-peened and magnetic particle inspected to ensure high-level performance
  • Gas key secured by grade 8 hardened fasteners and properly staked

*The carrier is fully protected by NiB-X underneath the topcoat; however, the TIN topcoat will wear on sliding surfaces.


  • Caliber: 5.56 NATO / .223 Rem. / 300BLK
  • Weight: 11.75 oz.
  • Finish: NiB-X Nickel Boron with TIN Topcoat
  • Material:
    • Carrier: Case hardened 8620 Steel
    • Gas Key: Tool Steel
    • Extractor: Tool Steel
    • Cam Pin: 4140 Steel
    • Bolt: Carpenter 158 Steel
  • Profile: Full-Auto

**A full-auto (A.K.A. M16) bolt carrier installed in a standard semi-auto AR-15 will not make the gun fire full-auto.


  • AR-15


  • 1x NiB-X Nickel Boron Bolt Assembly
  • 1x NiB-X Nickel Boron Extractor
  • 1x NiB-X Nickel Boron Cam Pin
  • 1x NiB-X Nickel Boron with TIN Topcoat Bolt Carrier
  • 1x NiB-X Nickel Boron Carrier Gas Key
  • 1x Firing Pin
  • 1x Firing Pin Retaining Pin


If you're looking for a bolt carrier group with increased wear resistance, the WMD Guns NiB-X Nickel Boron Bolt Carrier Group w/ TIN Topcoat is the way to go.

More Shooting Time and Less Cleaning Time

The WMD Guns NiB-X Nickel Boron Bolt Carrier Group w/ TIN Topcoat is an excellent upgrade because it allows for reduced fouling adherence, this means that the gun will not become as dirty, making it easier to clean so you can shoot more rounds between cleanings. In addition, you can easily wipe away any dirt, debris, or gunk that may have accumulated; this is critical because it means you can keep your gun looking and working like new longer.

Smoother and Cooler

The NiB-X Nickel Boron coating is extremely slick and reduces friction. Therefore, it reduces the need for lubrication. On top of that, this advanced coating allows your bolt carrier group to run more smoothly and with less heat buildup.

Please note that the TIN (gold) topcoat is a cosmetic finish, and it will have wear marks on the contact surface. But don't worry; the entire carrier is coated with NiB-X Nickel Boron underneath, so even if some of the TIN topcoats wear off, it will not affect the performance of the BCG.

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