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.