 Its carrying handle is an external part of the bolt group, which is cycled by redirected propellant gas as part of the operating system, but unlike the M16 rifle propellant gasses are not vented into the receiver; it also functions as the charging handle and forward assist.Once the bolt group starts to recoil, remaining gasses are immediately vented outward and spent cases are ejected directly upwards.To manage recoil the weapon has a large, twin-port muzzle brake, thick rubber butt pad, and an internal buffer to the rear of the bolt group, but recoil is still harsh and only semi-automatic fire is viable when not mounted.