Demand for personal defense weapons chambered in calibers like 5.7x28mm has been steadily growing over the years but picking the right platform can be a tough decision. If the modularity of the Mk4 AR15 platform piques your interest then this RESOLUTE® Mk4 in 5.7x28mm is the thing for you. Instead of using pistol magazines this RESOLUTE uses our new generation of 5.7 magazines that fit standard AR15 magwells for maximum modularity. - When full-size rifles are too cumbersome and pistols/SBRs don’t deliver the long-range ballistic performance you need the CMMG RESOLUTE line of carbine length rifles is the answer. Fitted with the suite of ZEROED parts and accessories as well as our legendary RIPSTOCK the RESOLUTE is the rifle that’s never out of place. The new EML 15 handguard brings style to the next level. M-LOK® attachment slots are found where expected at the 3 6 and 9 o’clock positions as well as on top at 12 o’clock with the omission of a full-length Picatinny section found on our previous handguard. This reduces weight while the additional M-LOK section still gives shooters a place to mount those must-have accessories. With a range of choices just pick the caliber you need for the job and let your rifle do the talking. - Platform Mk4 - Caliber 5.7x28mm - Operating System Radial Delayed Blowback - Barrel Length 16.1 - Barrel Twist 1:9 - Barrel Contour MT - Barrel Material 4140CM SBN - Barrel Twist 1:9 - Muzzle Device CMMG ZEROED Muzzle Brake - Muzzle Thread 1/2 x 28 - Upper Receiver Billet 6061 T6 Aluminum - Lower Receiver Mk4 Forged 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 - Receiver Extension CMMG 6 Position Fastback w/Ambi Sling Plate - Stock / Brace CMMG RipStock - Trigger Type ZEROED Drop-In - Trigger Guard CMMG ZEROED Trigger Guard - Safety Selector CMMG ZEROED 60/90 Degree - Magazine CMMG 32rd - Weight 6.4 lbs - Length 32.5