Automatic grenade launcher

An automatic grenade launcher or grenade machine gun is a grenade launcher firing rounds in quick succession from an ammunition belt or large-capacity magazine. They can be attached to a tripod. Automatic launchers include the Mk 19, Vektor Y3, AGS-17, and the HK GMG, which all fire at a higher velocity than related shoulder-fired grenades. They generally function as large-caliber machine guns with a relatively low rate of fire, used from an emplaced position in a similar way to a heavy machine gun.

The heavy equivalent of the XM29 is the XM307 ACSW automatic grenade launcher that is easily convertible between the 25 mm grenade ammunition and standard .50 BMG cartridges. Both are intended to fire programmable "smart" grenades capable of being set to explode at a certain distance from launch or at a certain height above the ground. This gives the ability to hit targets inside rooms or behind hard cover that would normally not be reachable by small arms fire.

Portable variants
A man-portable automatic grenade launcher is the Type 87 of Chinese origin, which is capable of firing up to 500rpm in full automatic.