WMD Guns NiB-X 300 Blackout 16″ Complete Upper Assembly

Built by one of the most innovative teams in the firearms industry, the WMD Guns 300 Blackout 16″ Upper Assembly delivers exceptional quality backed by a unique blend of metallurgy, chemistry, and gunsmithing expertise. WMD Guns is renowned for its proprietary NiB-X (Nickel Boron) coating process, developed and applied entirely in-house by a team of plating engineers and gunsmiths — resulting in superior corrosion resistance, reduced friction, and a self-lubricating surface that keeps your rifle running reliably in demanding conditions.

This 300 BLK upper assembly is chambered for one of today’s most versatile cartridges, capable of cycling both supersonic and subsonic ammunition — making it an outstanding choice for hunters, home defenders, and suppressor enthusiasts alike. The 16″ barrel configuration offers an excellent balance of velocity, handling, and compliance for a wide range of shooting applications.

Whether you’re building a custom AR-15 or upgrading an existing lower, this upper assembly is a premium drop-in solution that reflects WMD Guns’ commitment to precision and durability. Please note that many WMD Guns products are made to order — contact us for current availability and lead times.

At Deep Roots Rifle Co, we carry hard-to-find components like this WMD upper assembly and are ready to help you complete your build. Order online at deeprootsrifleco.com or stop by our gun store in Eustis, Florida to speak with our knowledgeable staff about this upper and other custom build options.