CMMG Banshee MK57 SBR 5.7 X 28 5 Barrel 20-Rounds

CMMG Banshee MK57 Features The CMMG Banshee MK57 is chambered in 5.7x28mm on a billet 6061 T6 aluminum upper and forged 7075 T6 MK57 lower with a 5-inch 4140CM Salt Bath Nitride barrel at a 1:9 twist rate and a CMMG ZEROED ambidextrous charging handle. The MK57 lower platform is designed to accept FN Five-seveN pattern magazines delivering 20+1 capacity while retaining the full AR-15 operational feature set including last-round bolt hold open and standard AR-15 trigger compatibility. At 4.9 lbs across a 21.3-inch overall length the Banshee MK57 delivers the smallest 5-inch MK57 SBR configuration CMMG offers. The Radial Delayed Blowback operating system adapted from the original .45 ACP MkG platform produces a softer recoil impulse and reduced bolt weight compared to traditional straight blowback pistol caliber AR designs improving controllability across 5.7x28mm rapid-fire strings. The EML4 M-LOK handguard provides attachment slots at the 3 6 and 9 o clock positions with a full-length Picatinny top rail integrated handstop and 1/2x28 threaded muzzle fitted with a CMMG ZEROED linear compensator. A CMMG ZEROED 60/90 degree safety selector integrated trigger guard mil-spec single stage trigger and ZEROED pistol grip complete the lower control package. CMMG engineered the Banshee MK57 around the MK57 lower platform which is purpose-built for 5.7x28mm and FN Five-seveN magazine use providing interchangeability between the Banshee MK57 and FN Five-seveN pistol magazine users. The 6-position CMMG Fastback receiver extension and RipStock deliver a configurable and fast-deploying stock solution suited to the compact SBR form factor. All ZEROED parts and accessories are manufactured in the USA to CMMG s quality and tolerance standards. CMMG Banshee MK57 Specifications Manufacturer: CMMG Model: Banshee MK57 Action: Semi-Auto Caliber: 5.7x28mm Operating System: Radial Delayed Blowback Barrel Length: 5 Barrel Material: 4140CM Salt Bath Nitride Twist Rate: 1:9 Capacity: 20+1 Overall Length: 21.3 Weight: 4.9 lbs Upper Receiver: Billet 6061 T6 Aluminum Lower Receiver: MK57 Forged 7075 T6 Aluminum Handguard: CMMG EML4 M-LOK Charging Handle: CMMG ZEROED Ambi Trigger: Mil-Spec Single Stage Safety: CMMG ZEROED 60/90 Degree Grip: CMMG ZEROED Pistol Grip Stock: CMMG RipStock Receiver Extension: CMMG 6-Position Fastback Muzzle Device: CMMG ZEROED Linear Compensator Muzzle Thread: 1/2x28 Magazine: FN Five-seveN Pattern 20rd Finish: Black Cerakote Sights: None Optic Ready