WMD .308 Bolt Carrier Group – NiB-X Nickel Boron POLISHED

• Carrier: Made with 8620 steel and case-hardened. Treated with nickel boron on all surfaces.
• Bolt: 9310 steel subjected to case hardening and fitted with Mil-Spec gas rings, extractor and ejector, all NiB-X® coated. Fit with specialized O-ring buffer. All bolts are magnetic particle inspected and shot peened to ensure quality.
• Firing pin: Hardened, heat-treated and chromed per Mil-Spec guidelines.
• Gas key: Hardened component secured with grade 8 fasteners, Permatex Sealing Compound and staking.
• Cam pin: Completely coated with NiB-X® for lubricity and ease of operation.

When you’re choosing components for an LR-10 build, a quality bolt carrier group is one of the most important considerations. This part is responsible for multiple steps in the gun’s order of operations, and it needs to be able to shrug off heat, wear, carbon buildup and the elements to make sure you’re always ready for anything. 

A nickel boron coating gives your .308 BCG that capability. This superlative finish is harder than chrome, provides exceptional resistance to corrosion and yields the lubricity needed to keep your firearm operational even under the harshest conditions.

Nickel boron is used to coat a variety of parts thanks to its desirable characteristics. It resists chemical degradation, heat damage, rust and wear, and it boasts a coefficient of friction of .6 along with a hardness rating of 70 on the Rockwell C scale. It also maintains those properties evenly throughout its structure for truly consistent protection.

In short, nickel boron is exactly what you want on an AR’s bolt carrier group. WMD Guns was part of the group that first tested this coating for firearm components, so we have in-depth, hands-on experience in delivering the best possible version of polished nickel boron for an LR-10 BCG. Our proprietary NiB-X® finish involves a formula and application method that survived a 30,000-round torture test with flying colors.

Today, there are many companies producing LR-10 receivers. Originally, there were considerably fewer, with ArmaLite and DPMS leading the field. DPMS’ LR-308 enjoyed considerably more popularity and saw the bulk of new designs following this pattern. 

If your LR-10’s upper has a curve at the bottom rear edge of its upper receiver, it uses the DPMS style and will readily accept this BGC. 

The WMD Guns team applies our top-tier coatings to premium, defense-grade parts to ensure our products offer consistent quality throughout.