The mortar has been around a very long time as a vital component of any army's artillery branch. In the modern day, this means a "Stokes Type" muzzle-loaded mortar. While most mortars in the world today range from 60mm to 81- or 82mm, there is a growing force of heavy mortars on the market, mostly in the 120mm class.
In an attempt to meet a critical need for the United States Marine Corps, General Dynamics Ordnance & Tactical Systems created the winning entry for the "Expeditionary Fire Support System":
While certainly not as large some mortars of yesteryear, the US Marine Corps' M327 120mm Rifled Mortar System (based on the French Army's RT F1) was selected as the primary weapon for the Expeditionary Fire Support System (EFSS) in 2011, following the demise of the 'Dragon Fire' modular 120mm mortar system. It fires all standard US Artillery 120mm mortar ammunition, and is capable of delivering everything from impact to air-burst munitions on target, out to a range of 8200m; under development is a rocket-assisted projection from Raytheon that will allow a 17km range, with a 20m Circular Error Probable (CEP) radius.
While a thoroughly conventional design, General Dynamics' offering is mostly notable for being purpose-designed to fit into the MV-22 'Osprey' tilt-rotor aircraft, as well as the AAV-P7/A1 Amphibious Assault Vehicle.
General Dynamics support system involves two Jeep-like Prime Movers, one to tow the mortar itself, and another to pull its ammunition limber, which holds thirty rounds. The Prime Mover vehicle is the Internally Transportable Vehicle (ITV), made by American Growler, of Robbins, North Carolina. The ITV weighs in at 4,000lbs, with a 2,000lbs load capacity. The Growler is not cheap, primarily due to the sophisticated suspension system necessary to lower the chassis for loading, then raise it to running height for maneuver after unloading. The system, while thoroughly tested, is not yet combat proven, unlike other systems such as the Rheinmetall 'Weisel' or the venerable BAE Hagglunds Bv-206. While the original Growler cost anywhere from $7,500 to $14,500 (depending on the exact model), and was passed partially on the M151 Jeep, the production version of the ITV will cost in excess of $209,000. Each.
Additionally, there are serious concerns as to the ITV's stability on the road, as it revives the Jeep's endemic tipping issues with a heavy engine and transmission (relative to its size), high center of gravity, short wheelbase and a narrow chassis. Of much greater concern, however, is the vehicle's lack of even minimal armor protection, and no anti-mine/IED shaping to the body.
To its credit, the Marine Corps is aware of the failings of the design, but budgetary concerns have precluded replacement of the system into at least 2018.
The EFSS is a necessary system. The Marine Corps needs, badly, an air-deployable system to deliver heavy mortars to the battle area. The question, though, is whether the Corps is trimming too much safety for too little of a return in tactical utility. It remains to be seen, both whether the Corps has made this calculation well, or whether the price will be prohibitively expensive in other ways.