The DDM4 300S AR15 style Upper Receiver Group is designed for those demanding a high-performance, short-barrel rifle chambered in the versatile 300 Blackout cartridge. Built around a 10.3 inch barrel, the 300S Upper Receiver Group uses standard 5.56 bolts and magazines to deliver .30 caliber projectiles with greater muzzle energy than comparable 5.56mm platforms. With a wide variety of factory ammunition made for everything from home defense, target shooting, hunting, suppressed operation, and tactical applications, this upper receiver group is capable of delivering exceptional performance from a compact, fast-handling package. The independently ambi GRIP-N-RIP Charging Handle accommodates left- and right-handed shooters. All Daniel Defense complete upper receiver groups come standard with an M16 profile bolt carrier group.