WMD Guns’ Bolt Carrier Groups are some of the best in the industry because of their coatings.  They are the leader in the nickel boron coating process.  With many other coating capabilities, you can be sure to find the BCG you’re looking for.  Some of their coatings include: NiB-X^® Nickel Boron, Nitromet Salt Bath Nitrocarburizing (i.e., Melonite), Electroless Nickel Teflon, Zinc Nickel, Electroless Nickel, DLC, PVD, and additional custom formulations.