Winchester Model 1912

The Winchester Model 1912 (also commonly known as the Model 12, or M12) is a hammerless slide-action, i.e., pump-action, shotgun with an external tube magazine. Popularly-named the Perfect Repeater at its introduction, it largely set the standard for pump action shotguns over its 51 year high-rate production life. From 1912 until first discontinued by Winchester in 1963, nearly two million Model 12 shotguns were produced in various grades and barrel lengths. Initially chambered for 20 gauge, only, the 12 and 16 gauge versions came out in 1914, and the 28 gauge version came out in 1934. A .410 version was never produced; instead, a scaled-down version of the Model 12 known as the Model 42, directly derived from scaled drawings of the Model 12, was produced instead.

Description
The Model 12 (introduced in 1912) was the next step from the Winchester Model 1897 hammer-fired shotgun, which in turn had evolved from the earlier Winchester Model 1893 shotgun. The Model 12 was designed by Winchester employee Thomas Crossly Johnson, and was based in large part on a design by John Browning. It was an entirely new design initially available in 20 gauge only (12 and 16 gauge guns were not sold until 1914). The Model 12 was the first truly successful internal hammer pump-action shotgun ever produced. Its tubular magazine was loaded through the bottom of the gun. Empty shotgun shells ejected to the right. Depending on the particular wooden transformer plug installed in the magazine, 2, 3, or 4 shells could be stored in the tubular magazine. The magazine holds 6, 2 3/4" 12 ga. shells. With forged and machined steel parts, the ultimate reason for discontinuation in 1963 was that it was too expensive to produce at a competitive price.  The primary competition at this time came from the much less expensive Remington Model 870, which had been introduced in 1950.  The majority of "modern" Model 12 shotguns manufactured after the 1930's were chambered for 2¾-inch shotgun shells, only. Some early Model 12's, however, were chambered for 2 9/16-inch shotgun shells.  To add further confusion, some of these early Model 12's have subsequently been modified, with their chambers lengthened to accept 2¾-inch shotgun shells, while others remain in their factory-stock 2 9/16-inch chamber lengths.  Careful inspection by a gunsmith is always recommended to determine whether or not it is safe to fire a modern 2¾-inch shotgun shell in older Model 12's.

Special commemorative examples were nonetheless produced by Winchester after 1963 through 2006, through specialized gun collector purchase programs, but the Perfect Repeater shotgun was never mass-produced after 1963. The Winchester factory announced a complete closing of the factory facility in January 2006, thus ending the Model 12's long and illustrious career at the age of 95 years.

Military Use
The United States military 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 when the Model 12's initial production ceased in 1963. 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 perforated steel heat shield and a M1917 bayonet adapter. In appearance, the Model 12 trench gun was very much like the Model 1897 trench gun.

More than 80,000 Model 12 shotguns were purchased during World War II by the United States Marines, Army Air Force, 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 US Army for use in protecting Army bases and in protecting Army Air Force aircraft against saboteurs when parked during World War II. The Navy similarly purchased and used the riot gun version for protecting US Navy ships and Navy personnel while in foreign ports. The US Marines used the trench gun version of the Model 12 to great success in taking Japanese-occupied islands in the Pacific during World War II. The primary difference in Model 12 shotguns between the World War II trench gun version versus the World War I trench gun version was that the original design, containing 6 rows of holes in the perforated heat shield, was reduced to only 4 rows during 1942.

During the Korean War, the US Marines used the Model 12 extensively. Likewise, the US Marines and Army used the Model 12 during the early part of the Vietnam War, until, due to the Model 12's production ending in 1963, and the high rate of wartime use, the Model 12 shotguns in inventory were consumed. The Ithaca 37 soon filled the void caused by the end of the Model 12's production, especially among U.S. Navy SEALS. Ironically, it had originally been designed specifically to compete with the Model 12 in the years just before World War II.

Unlike most modern pump-action shotguns, the Winchester Model 12 had no trigger disconnector. Like the earlier Model 1897, it too fired each time the action closed with the trigger depressed. That and its 6-shot capacity made it extremely effective for close-combat. As fast as one could pump the action, another shot would be fired, making the shotgun perhaps the most effective close combat weapon save for Thompson and M3 submachine guns. Unlike the submachine guns, however, the aiming of the Model 12 shotguns made it much more accurate in the typical combat usage, with many claims for one shot, one kill versus the more wasteful suppressing fire from submachine guns.

See List of individual weapons of the U.S. Armed Forces