.450BM Bolt Carrier Group NiB-X Nickel Boron POLISHED
.450BM Bolt Carrier Group NiB-X Nickel Boron POLISHED, NiB-X .450 BM, M16/AR-15 Full Auto Bolt Carrier Group - POLISHED All WMD BCG components are manufactured by Defense Industrial Base suppliers to WMD's exacting specifications to provide the best BCG available. Specifically engineered for NiB-X nickel boron coating to provide long life, high reliability and easy cleaning and maintenance.