Product Description The WMD Guns NiB-X Bolt Carrier Group (BCG) is built for AR-platform rifles chambered in .450 Bushmaster, combining best-in-class materials with WMD&&';;s high-performance NiB-X (nickel boron) coating for smooth cycling and enhanced reliability. Designed to perform in demanding conditions, this full-auto profile carrier group features a case-hardened 9310 steel bolt and precision-treated components to help deliver consistent operation and long service life. Product Highlights NiB-X (nickel boron) coated bolt carrier group for reduced friction and easier cleaning Compatible with AR-platform rifles chambered in .450 Bushmaster Case-hardened 9310 steel bolt for strength and durability Hardened, heat-treated, and chromed firing pin for dependable ignition Full-auto profile carrier with NiB-X coated cam pin Specs Brand: WMD Guns Product Type: Bolt Carrier Group (BCG) Platform: AR Caliber: .450 Bushmaster Finish/Coating: NiB-X (Nickel Boron) Bolt Material: Case-hardened 9310 steel Firing Pin: Hardened, heat-treated, chromed Cam Pin: NiB-X coated Carrier Profile: Full-auto UPC: 855899003577 Manufacturer Part Number: 1-NIBXBCG450BM Disclaimer: We strive to provide accurate and up-to-date product descriptions, specifications, and images; however, errors or omissions may occasionally occur. We are not responsible for any inaccuracies or discrepancies in the content provided. If you notice anything incorrect or unclear, please contact us so we can correct it. When in doubt, we recommend verifying details directly with the product&&';;s manufacturer.