The Expeditionary Fire Support System (EFSS) was developed in response to the USMC’s need for a fire support system that is lighter, more mobile and vertically transportable for missions requiring tactical versatility, speed and close-in fire support.

The EFSS expands the maneuver commander’s choices of fire-support capability against an array of targets including light-armored, motorized, and dismounted personnel; command and control systems; and indirect fire systems. The system’s Prime Mover vehicle along with the 120mm towed rifled mortar is designed to be internally transportable in the MV-22 Osprey,CH-53, C-130 and the C-5 aircraft.

The Expeditionary Fire Support System is comprised of a Prime Mover vehicle, 120mm towed rifle mortar weapon, a family of insensitive munitions (IM) compliant ammunition and the ammunition trailer.