They outrange light and medium mortars, and their explosive power is much greater.

High-explosive rounds fired by the M120 weigh about 31 lb (14 kg) and can have a lethality radius of 225 ft (69 m).

[2] The K6 entered service with the United States Army in 1991 as the M120 Mortar System.

Its mission is to provide heavy-weapon, high-angle organic indirect fire support to the unit commander.

Another feature of the M120 is the M303 sub-caliber insert, which allows the mortar to fire 81 mm ammunition.