The
United States armed forces used various versions of the Model 12 in
World War I,
World War II,
Korea, and in the early part of the
Vietnam War, until inventory was exhausted after the Model 12's initial production ceased in 1964. Versions of the Model 12 were type classified as the
Model 12 or
M12 for short. Approximately 20,000 Model 12
trench guns were purchased by the US Army in World War I, differing from the civilian version by having a shorter barrel, a perforated steel heat shield, and a
M1917 bayonet adapter. More than 80,000 Model 12 shotguns were purchased during
World War II by the
United States Marine Corps,
Army Air Forces, and
Navy, mostly for use in the
Pacific theater.
Riot gun versions of the Model 12, lacking the heat shield and bayonet, were purchased by the Army for use in defending bases and in protecting Air Forces aircraft against saboteurs when parked. The Navy similarly purchased and used the riot gun version for protecting Navy ships and personnel while in foreign ports. The Marine Corps used the trench gun version of the Model 12 to great success in taking Japanese-occupied islands in the Pacific. The primary difference between the World War I and the World War II Model 12 trench gun versions was that the original design contained six rows of holes in the perforated heat shield, this was further reduced to only four rows beginning in 1942. During the Korean War, the Marines used the Model 12 extensively. Likewise, the Marines and U.S. Army used the Model 12 during the Vietnam War. However, production of the Model 12 ended in 1964, which led to the Model 12 no longer being purchased by the military. However, there were numerous firearms already in the American arsenal, and the Model 12 would continue to see combat service until the end of the 1960s. During the middle 1960s, the
Ithaca 37 shotgun was acquired for combat use, and it began replacing the Model 12 as the primary shotgun employed by the United States military. The Ithaca 37 eventually became the most commonly used shotgun of the Vietnam War. Other shotguns which were used in that conflict included the Winchester Model 1897 trench gun, the Stevens Model 77 shotgun, and the Remington 870 Wingmaster, the latter of which was used more by the U.S. Navy than other branches. Unlike most modern pump-action shotguns, the Winchester Model 12 had no
trigger disconnector. Like the earlier
Winchester Model 1897, it fired each time the action closed as long as the trigger remained depressed from the prior shot. While the trigger remained depressed, as fast as one could pump the action open and closed another round would fire ("slam firing"). That capability and its six shell magazine capacity made it effective for close-combat.
See List of individual weapons of the U.S. Armed Forces ==Users==