bolt action british army 4 2 inch heavy mortar late warSupport your frontline British troops and rain down fire from afar with a Heavy Mortar! The 4. 2 inch heavy mortar was first used by the Royal Engineers at the Battle of El Alamein in 1942. From 1943 it was deployed as divisional support for infantry formations. A powerful weapon, it was usually treated more like supporting artillery than its lighter cousins. Mortars are some of the most widely used units in all of Bolt Action, giving your force the