 Smoke, illuminating and high explosive bombs are available.The 51 mm mortar replaced the World War II-vintage 2 inch mortar in the late 1980s.It was due to be phased out by the use of the 40 mm L17A2 UGL (underslung grenade launcher) mounted on the L85A2; however operational experience has led to the decision to replace it with a 60mm Mortar.