• NiB-X Nickel Boron finish inside and out
  • 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 coating off
  • Polished carrier to reduce fouling adherence
  • Especially beneficial in short barrel setups and suppressed platforms.
  • Heat-treated, shot-peened and magnetic particle inspected to ensure high-level performance
  • Gas key secured by grade 8 hardened fasteners and properly staked


  • Caliber: 5.56 NATO / .223 Rem. / 300BLK
  • Weight:
    • Full-Auto Profile: 11.71 oz.
    • Semi-Auto Profile: 11.22 oz.
  • Finish: NiB-X Nickel Boron
  • Material:
    • Carrier: Case Hardened 8620 Steel
    • Gas Key: Tool Steel
    • Extractor: Tool Steel
    • Cam Pin: 4140 Steel
    • Bolt: Carpenter 158 Steel
  • Profile: Full-Auto or Semi-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 Bolt Carrier
  • 1x NiB-X Nickel Boron Carrier Gas Key
  • 1x Firing Pin
  • 1x Firing Pin Retaining Pin
  • 1x NiB-X Nickel Boron Hammer (optional)


When you want to build a custom AR platform rifle, you’ll need a great bolt carrier group that’s designed for the rifle you want in the end. Wing Tactical carries a variety of bolt carrier groups that are ready for your next build, all you have to do is decide which one you want. A WMD nickel boron bolt carrier group can be an awesome selection for your next build. The WMD NiB-X Bolt Carrier Group is available in semi and fully automatic models with or without a hammer. Whichever one you need, a WMB BCG will give you great quality and cutting-edge coatings that will make your investment last longer and function smoothly.

WMD Bolt Carrier Groups feature NiB-X Coating

When you choose a WMD Bolt Carrier Group you get a complete NiB-X bolt carrier group. This includes a 158 Carpenter steel bolt that’s been heat treated, shot peened and magnetic particle inspected so you know that it’s strong and reliable. The extractor is hardened, heat treated and given the WMD proprietary NiB-X coating. Whether you choose the fully or semi-automatic version of the WMD NiB-X Bolt Carrier Group, your WMD BCG will include a heat treated, case hardened 8620 carrier body coated with the same next-generation NiB-X Nickel Boron coating that gives 40% greater wear life than Mil-Spec coatings. If you choose a WMD Nickle Boron Bolt Carrier Group you’re getting a BCG designed specially to be completed with NiB-X coatings for superior function and durability. The WMD Nickel Boron Bolt Carrier Group will give you an edge no matter what style of shooter you are.

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