There's a world of options when it comes to firearms and calibers and for those who want to reach out to further targets or hunt with 5.56 the 16-inch Br4 chambered in 5.56x45mm is an awesome choice. Despite all the different caliber offerings in the DISSENT lineup 5.56x45mm still stands as one of the most popular. Equipped with a 16.1 barrel this Br4 is one classy carbine. - Platform Br4 - Caliber 5.56x45mm - Operating System Compact Action-Direct Impingement - Barrel Length 16.1 - Barrel Twist 1:7 - Barrel Contour MT - Barrel Material 4140CM SBN - Barrel Twist 1:7 - Muzzle Device CMMG ZEROED Muzzle Brake - Muzzle Thread 1/2 x 28 - Gas Port Location Mid - Gas Block Adjustable 0.750 - Upper Receiver DISSENT 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) Magpul 10rd PMAG - Weight 8 lbs - Length 38.1