the m67 recoilless rifle was a 90 mm (3.55 inch) anti-tank recoilless rifle made in the united states and later in south korea. it could also be employed in an anti-personnel role with the use of the m590 antipersonnel round. it was designed to be fired primarily from the ground using the bipod and monopod, but could also be fired from the shoulder using the folded bipod as a shoulder rest and the monopod as a front grip. the weapon was air-cooled and breech-loaded, and fired fixed ammunition. it is a direct fire weapon employing stadia lines to allow simple range finding, based on a typical tank target bridging the lines once in range.