M320 Grenade Launcher Module

M320 Grenade Launcher Module (GLM) is the U.S. military's designation of a single-shot 40 mm grenade launcher system that aimed to replace the M203 for the U.S. Army, while other services initially kept using the older M203. The M320 uses the same High-Low Propulsion System as the M203. The M320 can be mounted on the M16 series of rifles, while the M320A1 can be mounted on the M4 series of carbines.
As of April 2026, the US Army issued a request for a next-generation grenade launcher to replace the M203 and M320.