The Radical Firearms 16” .450 Bushmaster HBAR Complete Upper Receiver is a law enforcement grade, drop-in solution for your next AR build. Crafted with quality materials and covered by Radical’s lifetime warranty, this MIL-SPEC upper receiver provides an outstanding solution for any budget. Arrives at your door with the hard work done. Complete this build with your favorite lower receiver and sights then head for the range! Features: - 16" 41V50 chrome moly vanadium steel HBAR barrel - Chambered in .450 Bushmaster with a 1:14 twist rate