One Horse OH-CU04 Complete Upper 300 Blackout 16"

The One Horse OH-CU04 is a complete AR-15 upper receiver assembly chambered in 300 Blackout, built around a 16" barrel. The 300 Blackout chambering is optimized for both supersonic and subsonic loads, making it versatile for hunting and tactical applications. Based on available supplier data, the upper operates on a direct impingement gas system with a carbine-length gas tube appropriate for a 16" barrel. The upper ships as a complete assembly ready to mate to any mil-spec AR-15 lower receiver. Muzzle threading follows standard 5/8-24 convention for 300 Blackout, compatible with suppressors and muzzle devices.