CMMG delivers its lightest and most compact firearms within the Banshee line of Short Barreled Rifles (SBR's) and AR pistols. Don't let these little guys fool you though - there's plenty of firepower in the Banshee upper. This upper receiver features a forged 7075-T6-AL M4 upper receiver assembly with a bolt carrier group. The Banshee is the right combination for you when concealment and portability matter the most. 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 bolt closed long enough to safely operate. With the RDB system the bolt must b...