Marching fire

Marching fire, also known as walking fire, is a military tactic; a form of suppressive fire used during an infantry assault or combined arms assault. Advancing units fire their weapons without stopping to aim, in an attempt to pin down enemy defenders. Marching fire usually ends with an infantry charge to engage the enemy in close combat. The tactic requires ample ammunition and rapid-fire weapons. It differs from fire and movement in that the attacking force advances in unison rather than leapfrogging forward in alternating groups.

An early form of marching fire was used with little success by Prussian troops at the end of the 18th century, then victoriously in the 1866 Battle of Königgrätz because of the fast-firing Dreyse needle gun. The modern form of marching fire evolved in the early 20th century from a French Army infantry assault concept which suggested the use of suppressive fire from a light machine gun carried by one man—the Chauchat automatic rifle. The tactic was employed to a limited degree in World War I then further codified with the introduction of the M1918 Browning Automatic Rifle and described in U.S. small unit infantry tactics manuals in the early 1920s. As a combined arms stratagem, the tactic was prominently advocated and utilized by General George S. Patton in World War II during his command of the Third Army.

...
Wikipedia