The One Horse 5.56 NATO Complete Upper Receiver is a purpose-built AR15 upper designed to deliver dependable accuracy, smooth cycling, and modular versatility. Built around a 16-inch 5.56 NATO barrel, this complete upper arrives fully assembled and ready to pin onto any Mil-Spec lower receiver. Whether you’re upgrading an existing rifle or completing a new build, this upper provides a reliable, work-ready foundation for range use, training, and defensive applications. Proudly made in the USA, it reflects a no-frills approach focused on performance and durability.

Built for dependable rifle setups, this 16-inch 5.56 NATO complete upper combines a SOCOM-profile barrel, mid-length gas system, and 15-inch free-float M-LOK handguard for balanced performance and accessory flexibility. The included nitride bolt carrier group and charging handle make it a ready-to-mount option for Mil-Spec AR-15 lowers, while the full-length Picatinny rail gives you plenty of room for optics and other sighting accessories. Features 15-inch free-float M-LOK handguard with full-length Picatinny top rail Clamp-on handguard system with steel barrel nut and screws