The M203 is a single-shot, 40mm grenade launcher designed to be attached to various firearms, primarily the M16 and M4 rifles. It allows soldiers to fire explosive grenades at targets from a distance, enhancing their combat capabilities. The M203 is lightweight and can be operated by a single soldier, making it a versatile tool in military operations. Introduced in the late 1960s, the M203 has been widely used by the U.S. military and other armed forces around the world. Its design includes a rifled barrel for improved accuracy and a simple sighting system, making it effective for both direct and indirect fire.