One Horse, 5.56 NATO, 16 Barrel, 15 Handguard, Nitride BCG, Complete Upper Receiver

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