The hunt for your next personal defense weapon is over. Chambered in 5.7x28mm this Mk57 BANSHEE utilizes an 8 barrel to maximize the full potential of the 5.7x28mm round as a close-range personal defense caliber. Built on the Mk57 platform this BANSHEE accepts FN®* Five-seveN®* pattern magazines and features an intuitive oversized mag release. Rest assured that even with the use of pistol mags conventional AR functionality like last round bolt hold open is here to stay in the Mk57. – Platform Mk57 – Caliber 5.7x28mm – Operating System Radial Delayed Blowback – Barrel Length 8 – Barrel Twist 1:9 – Barrel Contour MT – Barrel Material 4140CM SBN – Barrel Twist 1:9 – Muzzle Device CMMG ZEROED Linear Compensator – Muzzle Thread 1/2 x 28 – Upper Receiver Billet 6061 T6 Aluminum – Lower Receiver Mk57 Forged 7075 T6 Aluminum – Hand Guard CMMG EML7 M-LOK – Finish Cerakote Standard – Charging Handle CMMG ZEROED Ambi – Pistol Grip CMMG ZEROED Pistol Grip – Buffer Type Carbine – Receiver Extension CMMG 6 Position Fastback Extension – Stock / Brace CMMG RipBrace – Trigger Type ZEROED Drop-In Single Stage – Trigger Guard Integrated – Safety Selector CMMG ZEROED 60/90 Degree – Magazine 20rd Promag – Weight 5.2 lbs – Length 23.7