The M2 4.2 inch Mortar was a heavy mortar used by the United States during World War II.
Description[]
The M2 could fire 107 (4.2 inch) mm rounds at a maximum range of 4,200 m.[1] Unusual to most others, the barrel of the M2 was rifled, removing the need to have stabilizing fins on the mortar rounds. Because the mortar was often assigned to chemical mortar units, the M2 was also often given the name of 'M2 Chemical Mortar', though the mustard gas rounds assigned to be used with the weapon were never used in the conflict.[2]