Tsunami Arms Type-18 Automatic Grenade Launcher

Tsunami Arms Type-18 Automatic Grenade Launcher aka Tsunami Arms "MicroMortar" AGL  is bulky, bazooka-like weapon is connected to a heavy (25 kg) backpack-sized magazine of grenades, so you can rain them on your enemy. A magazine change requires at least 4 actions. SDF soldiers nicknamed it ''The Pitching Machine". It has a gyro-balancer and recoil compensation, but the gunner will still suffer -1 REF and -1 MA from the weight and bulkiness of this thing.

Source

 * Pacific Rim, pg.19
 * Blackhand's Street Weapons, pg.37