• Drop-in 5.56 bolt for Mil-Spec carriers
  • Heat treated, shot peened, and magnetic particle inspected
  • NiB-X Nickel Boron finish provide long life, ease of cleaning and superior locking and unlocking action


  • Caliber: 5.56 NATO / .223 Rem. / 300 Blackout
  • Material: Carpenter 158 Steel
  • Finish: NiB-X Nickel Boron
  • Weight: 1.55 oz.


  • AR-15 (.223/5.56/.300BLK)


When you build a new AR-15, your build list is going to be a little unwieldy, it’s part of the game. If you’re choosing individual components rather than kits, you’ll have a lot to consider, but you’ll also have the opportunity to choose the best components without worrying about having to sort out pieces you don’t like. When it comes time to choose a bolt, there’s an option that can save you cleaning time and ensure that your weapon operates smoothly for a good long service life. Wing Tactical offers a WMD 5.56 bolt assembly we know you’ll love for your next AR build. The WMD NiB-X Bolt Assembly is their very own NiB-X bolt designed and manufactured to excel using their proprietary NiB-X coating process.

Why Do I Want a Nickel Boron Bolt?

Nickel Boron makes a superior bolt coating because it requires little additional lubrication for smooth function. That means there’s less extra lube to attract grit and fouling so cleaning will be an easier, less frequent chore. Nickle Boron coatings don’t hold grime on surfaces thanks to that same self-lubricity that allows you to leave off the extra lube. Smooth function has to be a top priority when choosing a nickel boron bolt for your new custom AR build.

What Makes a NiB-X WMD Bolt Different?

WMD Guns’ NiB-X coating is a proprietary application method for Nickel Boron coatings. The WMD NiB-X provides a more durable, longer-lived coating than standard Nickel Boron application methods. When you choose components with WMD’s NiB-X coating you can expect a 40% greater service life than traditional Mil-Spec coatings.

Have a question?

Ask an Expert