CMMG Resolute BR4, Semi-automatic, Rifle, 9MM, 16.1 Barrel, 1/2x28 Threaded, ZEROED Muzzle Break, Cerakote Finish, Armor Black, 15 M-LOK Handguard, Reversible Dissent Side Charger, Magpul SGA Remington 870 Stock, ZEROED Drop-In Single Stage Trigger, Reversible Cross Bolt Safety, 10 Rounds, 2 Magazines 94AC80F-AB 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 CMMG's 9mm DISSENT lineup. The 9mm Br4 uses CMMG's 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.