CMMG AR-15 Resolute Complete Upper Receiver 9mm Luger 16" Barrel

The Radial Delayed Blowback (RDB) system was created from the ground up by CMMG to eliminate problems with traditional blowback systems found in pistol caliber AR-15's. The biggest advantage of the RDB system is a gun that weighs less while simultaneously having less felt recoil. With a traditional blowback system, the only thing keeping the chamber closed is the weight of the bolt and action spring tension. As a result, the more powerful the cartridge is, the more weight is needed to keep the b