The WMD Guns NiB-X bolt carrier group is a complete BCG for AR-15 rifles chambered in 5.56. It is finished in nickel boron, a slick, hard coating that reduces friction and makes the carrier easier to clean than a phosphate finish. A drop-in upgrade for a new build or a replacement for a worn factory BCG.
- Brand: WMD Guns
- Type: complete bolt carrier group
- Fits: AR-15
- Chambering: 5.56
- Finish: NiB-X nickel boron
