Definition/Scope: (Army.mil) A conventional smoothbore, muzzle-loaded mortar system that provides increased range, lethality and safety compared to the World War II-vintage 4.2-inch (107mm) heavy mortar system it replaced in mechanized infantry, motorized, armored, and cavalry units. It is employed in towed (M120) and carrier-mounted (M121) versions and in the Stryker Brigade Combat Team mortar carrier. It fires a family of enhanced, U.S.-produced ammunition. The M120 towed system consists of the M298 Cannon (tube), M190 Bipod, M9 Baseplate, and the M67 Sight Unit. The M121 tracked carrier version consists of the M298 Cannon, M191 Bipod, M9 Baseplate, and the Carrier Adaption Kit. With the use of an auxiliary M9 Baseplate and extension feet for the M191 Bipod, the M121 can be dismounted from the vehicle and emplaced for ground-mounted operation.
Related Terms:M102 towed howitzer