Designed with the goal of utilizing as many existing AR15 components 300BLK gives shooters a variety of .30 Cal power to suit their taste. From subsonic to supersonic loadings with a long list of bullet types to match the 16.1 barrel on this DISSENT® upper group extracts every bit of performance without compromise. Perfect for swapping calibers on your existing DISSENT lower or starting a new build that ditches the AR buffer tube. - Utilizing our patent pending direct impingement Compact Action DISSENT upper groups house the entire action and recoil assembly in the upper receiver resulting in less bulk and length than traditional AR pistols. The forward non-reciprocating side charger allows for quick bolt operation without coming off target. Direct impingement DISSENTS come equipped with a left side charger standard. - All DISSENT Upper groups include a 1913 Picatinny rail end plate to use in place of the lower receiver buffer tube. - Adjustable Gas Block - 300 BLK is an incredibly adaptable cartridge with different loadings for specific uses like suppressed. With the adjustable gas block on each 300 BLK DISSENT you can fine tune the gas system to best suit the supersonic or subsonic ammo loadings you like best.- Platform Mk4 - Caliber .300 BLK - 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 5/8 x 24 - Gas Port Location Carbine - Gas Block Adjustable 0.750 - Upper Receiver DISSENT 7075 T6 Aluminum - Hand Guard CMMG 15 Proprietary - Finish Cerakote - Charging Handle DISSENT Side Charger- Left - Receiver Extension 1913 Picatinny Rail End Cap - Weight 4.85 lbs - Length 25.5