M320/M320A1 Grenade Launcher Module (GLM)

M320/M320A1 Grenade Launcher Module (GLM)

Enabling battlefield dominance while lightening the Soldier’s load with modularity.

The M320/M320A1 40 MM Grenade Launcher Module (GLM) is a lightweight grenade launcher that attaches under the barrel of the M16 series rifles (M320) or the M4 series carbines (M320A1). The M320/M320A1 Grenade Launcher enables Soldiers to accurately engage the enemy in daylight or total darkness out to 400 meters with 40mm low-velocity grenades. The M320 will replace all M203 series grenade launchers mounted on the M16/M4 series of rifles and carbines. The M320 can be mounted on the M16 series of rifles, while the M320A1 can be mounted on the M4 series of carbines. The weapon includes a side-loading unrestricted breech that permits the system to fire longer 40mm projectiles (NATO standard and non-standard). The system comes with a hand-held laser range finder and a Grenadier Sighting System.

The Grenadier Sighting System (GSS) provides the capability to accurately engage targets day and night with the M320 GLM. The GSS features include a reflex optical sight with integral back up iron sights, near infrared (NIR) aiming laser engagement for night engagements, NIR illuminator for increased detection and recognition at night, user selectable ballistic solution for up to 16 ammunition types, including quick selector for two pre-programmed ballistic solutions, atmospheric temperature and pressure sensors for ballistic compensation, and a cant indicator for increased accuracy when firing. The GSS replaces the previously fielded day night scope.


  • Caliber: 40mm
  • Weight: 5.0 pounds (without buttstock); 7.0 pounds (with buttstock)
  • Length: 11.18 inches (without buttstock); 14.37 (with buttstock retracted); 19.69 inches (with buttstock extended)
  • Barrel Length: 8.46 inches
  • Range: 400 meters