Forget what you thought you knew about Pistol Caliber Carbines the DISSENT Br4 brings classic rifle ergonomics together with the fixed ejector Radial Delayed Blowback technology of our 9mm DISSENT lineup. The 9mm Br4 uses our 9mm conversion magazines which also means that the Br4 lower will accept other STANAG pattern magazines if you decide to swap to another Mk4 DISSENT upper group. - Platform Br4 - Caliber 9mm - Operating System Compact Action-Radial Delayed Blowback - Barrel Length 16.1 - Barrel Twist 1:10 - Barrel Contour MT - Barrel Material 4140CM SBN - Barrel Twist 1:10 - Muzzle Device CMMG ZEROED Muzzle Brake - Muzzle Thread 1/2 x 28 - Upper Receiver DISSENT PCC 7075 T6 Aluminum - Lower Receiver Br4 Billet 7075 T6 Aluminum - Hand Guard CMMG 15 Proprietary - Finish Cerakote - Charging Handle Dissent Side Charger- Reversible - Stock / Brace Magpul SGA- Remington 870 - Trigger Type ZEROED Drop-In Single Stage - Trigger Guard Integrated - Safety Selector Reversible Cross Bolt - Magazine (2) CMMG 10rd - Weight 7.8 lbs - Length 38.1