8.6 BLK the round that gives you more rifle with less barrel. Thanks to the quick 1:3 twist rate 8.6 BLK hits it full ballistic potential with a much shorter overall barrel length compared to its AR10 contemporaries. If you’re a fan of hunting suppressed then this is definitely the round for you grab your new 8.6 BLK RESOLUTE® suppressor and subsonic ammo and show those 300 BLK fans what stopping power means. – Platform Mk3 – Caliber 8.6 BLK – Operating System Direct Impingement – Barrel Length 16.1 – Barrel Twist 1:3 – Barrel Contour MT – Barrel Material 4140CM Nitride Finish – Barrel Twist 1:3 – Muzzle Device CMMG ZEROED Muzzle Brake – Muzzle Thread 5/8 x 24 – Gas Port Location Carbine – Gas Block Adjustable 0.750 – Upper Receiver Billet 7075 T6 Aluminum – Lower Receiver Mk3 Billet 7075 T6 Aluminum – Hand Guard CMMG EML15 M-LOK – Finish Cerakote – Charging Handle CMMG ZEROED Ambi – Pistol Grip CMMG ZEROED Pistol Grip – Buffer Type Carbine Mk3 – Receiver Extension CMMG 6 Position Fastback w/Ambi Sling Plate – Stock / Brace CMMG RipStock – Trigger Type ZEROED Drop-In Single Stage – Trigger Guard Integrated – Safety Selector CMMG ZEROED 60/90 Degree – Magazine Magpul 20rd PMAG – Weight 8 lbs – Length 34