The Metal Storm 3GL is a three-round semi-automatic 40mm grenade launcher. Like the M320, it can be used as a standalone weapon, or mounted on some Assault Rifles. Its higher capacity gives it an advantage over single-shot launchers, and is much smaller and lighter than traditional multiple grenade launchers such as the M32 MGL. It uses the superposed load system where multiple projectiles are loaded nose to tail in a single gun barrel with propellant packed in between.