M203 Grenade Launcher

The M203 is a single-shot, pump-action 40mm grenade launcher designed by AAI Corporation to attach beneath the barrel of a rifle, originally the M16 rifle and later the M4 carbine. It fires the same 40x46mm SR ammunition as the earlier stand-alone M79 launcher, using a high-low propulsion system to reduce recoil, with the host rifle's own magazine well acting as a forward grip; because the rifle's iron sights do not align with the launcher's trajectory, a separate sight is fitted. Adopted by the United States in 1969, it has remained in service since, manufactured over the years by Colt Defense, Diemaco and several other makers.