The M203A1 is a 40mm, single shot, breech loaded, pump action, shoulder fired grenade launcher. It is used by both American and Canadian forces. It is mounted under the barrel. It ranges from 100-400m adjustable in 50m increments. The most commonly used rounds are smoke, CS, and HE rounds. It weighs 1.3kg unloaded and 1.8kg loaded depending on the round. It is simple to operate, take apart, and clean.
The M203 Grenadier took out a trench from 350m.