What size round is fired from the M203?

The M203 is an underslung grenade launcher that is designed to fire 40mm grenades. This system is classified as low velocity, which means it fires projectiles at a relatively lower speed compared to other grenade launchers or firearms. The 40mm designation indicates the diameter of the round, and it is specifically designed for use with a variety of 40mm ammunition types, such as high-explosive, smoke, and illumination rounds.

The low velocity designation allows for greater accuracy and controllability at shorter ranges, making the M203 effective for close support roles in various combat scenarios. This distinguishing feature of firing 40mm rounds is integral to the weapon’s design and functionality, providing versatility in firepower for the personnel using it.