WMD NIB-X Bolt Assembly was engineered for NiB-X nickel boron coating to provide long life, ease of cleaning, and superior locking and unlocking action with barrel extensions. Made with case-hardened 9310, shot peened, magnetic particle inspected, with high-performance extractor, ejector springs, gas rings, and special O-ring buffer, and a NiB-X coated bolt and extractor.
Caliber: .223/5.56
Caliber: .223/5.56
