Radian Weapons 6mm ARC 18" Complete Upper Receiver Gray

Radian Weapons machines uppers to a tolerance standard most AR builders only claim, and this complete 18 inch 6mm ARC upper shows why the brand commands a premium. The 6mm ARC cartridge brings genuine long range ballistics to the AR-15 footprint, staying supersonic well past 1,000 yards with match bullets while giving up little to cartridges that need a larger action.

An 18 inch barrel makes the most of that efficiency, building enough velocity for real precision work without stretching the package to lengths that fight you in the field. Finished in gray, it drops onto any standard AR-15 lower. Pin it on, zero it, and you have a legitimate precision gas gun.