Winchester Model 12 Shotgun: The Other Trench Gun

The Winchester Model 97 Trench Gun is the most recognized and iconic U.S. military shotgun. It looks deadly and is deadly. But in the view of many who used shotguns in the U.S. wars of the 20th Century, the Winchester Model 12 Trench and Riot Shotguns were the most effective.

The Model 12 was introduced to the commercial market in 1912, though initially it was only offered in 20-­gauge. 12-­gauge Model 12s became available in 1914. At first glance, it was obvious that the Model 12 was more streamlined. It didn’t have an exposed hammer and it had a longer receiver, so the bolt was not exposed during operation. From the military point of view this made it less susceptible to dirt, sand, etc. and also meant there was less chance of the bolt catching on something as the pump action was operated. Unlike the Model 97 Trench and Riot Guns, which relied on cocking the hammer with the thumb to prepare the weapon for action, the Model 12 had a cross bolt safety. But one feature of the Model 97 that was kept on the Model 12 was its ability to “slam fire” (i.e. keep firing with the trigger held back while the pump action was operated). This ability to fire quickly made the Models 97 and 12 combat shotguns very fast for clearing a trench or breaking a jungle ambush. However, once the action is locked, with the bolt forward, releasing the slide lock with thumb or forefinger or pulling the trigger is necessary to release the slide lock to allow operation of the pump action.

The Model 12 saw only limited usage in World War I. Although one or more prototype Trench models were developed, none appear to have seen combat. However, Model 12 Riot Guns were acquired for military use during World War I. For clarity, in this article the term “Trench Gun” will be used to describe those short-­barreled combat shotguns fitted with a handguard/bayonet adaptor and “Riot Gun” will be used to describe those military combat shotguns that did not have the handguard/bayonet adaptor. In many cases, both versions of the shotgun were acquired for military use. For example, though the Model 97 Trench Gun is better known, Model 97 Riot Guns were also acquired.

During the years between World War I and World War II many Winchester Model 97 and Remington Model 10 Trench Guns that had been used in World I remained in arsenals and were issued for use during the Banana Wars, to protect the U.S. Mail when Marines were assigned to that mission, and other tasks.

It was during World War II that the Winchester Model 12 Trench Gun was issued in significant numbers and saw combat, especially in the Pacific. According to Canfield in Complete Guide to United States Military Shotguns, a total of 61,104 Model 12, 12-­gauge shotguns were delivered to the U.S. Government during the War. The majority of these were Trench Guns, though there were also some riot guns and some longer barreled shotguns used to train aerial gunners. The Marines found the combat shotgun effective in jungle warfare. Point men, especially, liked the shotgun’s close-­range effectiveness. Trench Guns were also appreciated for breaking banzai attacks. As a result, the table of organizational equipment (TO&E) for the 2nd Marine Division called for 490 combat shotguns. Shotgun ammunition was problematical for the Marines as it was often in short supply, effective carrying pouches had to be improvised, and paper shotgun shells would swell in the wet conditions in the Pacific causing failures to feed. The answer was to use brass shotgun shells, which by the end of the war had been standardized as the M19 brass buckshot round.

After World War II, the U.S. armed forces standardized on three combat shotguns: Winchester Model 12 Trench Gun, Stevens 520-­30 Trench Gun, and Stevens 620A Trench Gun. However, Model 97 Trench Guns and other models remained in some armories. The Marines continued to use the shotgun — primarily the Model 12 Trench Gun —­ in Korea against “human wave attacks,” reportedly sometimes with bayonets affixed! The Model 12 Trench Guns saw such hard usage in Korea that most of those that had not been overhauled after World War II were overhauled after the Korean War.

After the end of combat in Korea in 1953, many of the remaining U.S. combat shotguns went into storage and/or were overhauled. Prior to the commitment of large numbers of ground troops to Vietnam some newly manufactured U.S. riot guns, such as the Ithaca Model 37 and Winchester Model 25, were supplied to South Vietnamese forces. A few of these were used by U.S. Special Forces advisors; though some members of Special Forces were using the old standby Winchester Model 97 and Winchester Model 12 Trench Guns. There were also reportedly some new Model 12 Trench Guns manufactured for the South Vietnamese before the model was discontinued in 1964.

Once U.S. ground troops were committed to combat in Vietnam, some of the overhauled World War II/Korean War Trench Guns were re-­issued, including the Winchester Model 12, Stevens 520-­30, and Stevens 620A. Of these, the Model 12 Trench was the most popular, especially with the Marines. Although the Model 12 saw use throughout the Vietnam Conflict, the exigencies of combat in a jungle counterinsurgency required the acquisition of additional new combat shotguns, primarily the Ithaca 37 and Savage 77E in riot gun configuration. The Ithaca 37 was especially popular with the U.S. Navy SEALs who appreciated that it retained the “slam fire” capability of the Winchester Models 97 and 12, allowing rapid engagement during an ambush or in breaking an ambush. The SEALs equipped a limited number of Ithaca Model 37s with a spreader choke to increase the horizontal spread of the buckshot pattern.

In Vietnam, conditions were similar to those of the jungle fighting in the South Pacific where paper shotgun shells would cause malfunctions due to swelling. Fortunately, the U.S. armed forces still had a supply of M19 brass 00 Buckshot shells for issue in Vietnam. As the supply of M19 shells became depleted, plastic-­cased shot shells that were also moisture resistant were acquired. The XM162 00 Buckshot load was adopted, as was the XM257 #4 Buckshot load. The #4 Buckshot loads were preferred by the SEALs for use in their “Duck Bill” shotguns with the spreader choke. One other load that saw limited use should be mentioned: the “Whirlpool” round was loaded with flechettes, which theoretically allowed longer range engagement because of their aerodynamic design. During tests between May 1967, and February 1968, flechette rounds were tested against XM162 00 Buckshot and XM257 #4 Buckshot. Reportedly, the flechettes registered “one shot kill” lethality during the tests. Though evaluated by both the Army and Marines, flechette loads did not see wide usage. Reportedly, the Marines were more impressed with them so at least some “Whirlpool” loads were probably fired from the Model 12 Trench Gun.

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For carrying shotgun shells in Vietnam, the standard issue pouch was a 1960s production version similar to the World War II M1938 pouch. Normally made of olive-­green canvas, the pouches held 12 shotgun shells in loops. MPs or other personnel pulling security details armed with a shotgun might carry one of these belt pouches. Troops carrying shotguns in combat, however, often improvised pouches to carry more shells. M16 pouches, first aid pouches, et. al. were used.

Although all U.S. combat shotguns are interesting, this article is focused primarily on the Model 12 Winchester in Vietnam. As mentioned earlier, the M12 Trench Gun was used most widely among Marines in Vietnam. It was popular with point men, who might have to engage multiple enemy quickly at close ranges. Shotguns were used sometimes during village searches to cover troops entering “hooches” or to cover a tunnel exit. The combat shotgun was also used to guard prisoners or in patrolling the perimeters of bases. Static guard posts might also have some personnel armed with the shotgun and some with the rifle. In some units during the early years of M16 issuance, problems with the rifle caused units to request additional shotguns for close range lethality and to cover riflemen with cases that had failed to extract from their M16s. Bottom line: the combat shotgun was valued for close range lethality!

The only friend I had who carried an M12 Trench Gun in Vietnam was a Marine who lost both legs to a mortar round but got on with his life and rode his Harley everywhere. He died some years ago, so I couldn’t call him, but I do remember that he felt the Model 12 was his best choice when acting as point men. He also carried an M14A1 a lot of the time.

As I hadn’t shot my Model 12 Trench Gun in more than 20 years I ran it through a re-­familiarization course. First, for anyone not familiar with the Model 12 Winchester, it has a bead front sight. Tubular magazine capacity is five rounds, which are loaded by pushing into the tubular magazine against spring pressure while pushing up the follower. Located on the left side of the receiver behind the trigger guard is the slide lock button, which releases the forearm to be pulled to the rear opening the breech. If the M12 is carried with an empty chamber but the internal hammer is cocked, a faster method is to just pull the trigger and pull the forearm to the rear. As mentioned previously, the M12 functions as a slam fire, so as long as the trigger is held back, each time the pump action is operated it will fire once it returns to battery.

I fired the Model 12 Trench Gun using two loads that would have been available in Vietnam. I used a Federal 2¾" #4 Buckshot round with 27 pellets to approximate an M257 load and a current GI 00 Buckshot, which is the same load as the Vietnam era M162 (NOTE: Once fully standardized the “X” was dropped from the designations for these loads). I fired both the #4 and 00 Buckshot loads at 25 yards and also the 00 Buckshot load at 15 yards. In all cases patterns would have likely been lethal, especially in the smaller VC or NVA personnel.

A friend and I then set up a scenario to test the applicability of the slam fire shotgun in a “meeting engagement” by a point man and an enemy patrol. We found a patch of trees that were located so a berm was still behind them and placed three targets amidst the trees spaced between 30 and 40 feet away. Upon a signal, I then engaged each target from closest to furthest as fast I could by holding back the trigger and operating the pump action as fast as I could. Because of recoil it was still necessary for me to pull the shotgun back onto the target as I moved among the targets, but patterns would have been incapacitating. The furthest target was locating behind intervening branches but the 00 buckshot pushed through to impact “center of mass” on the silhouette target. Bottom line: the Model 12 Trench Gun still would have performed its mission more than 75 years after it was first called to duty in World War II.

Although I’ve been interested in collecting and shooting U.S. military weapons for most of my adult life, the Trench Shotguns have always been my favorites. Admittedly the Model 97 Trench Gun is iconic, which is why I used it for the shooting demonstration in my book on U.S. Combat Shotguns in the Osprey Weapon series, but my favorite has always been the Model 12 Trench Gun. It still is after shooting it a couple of days ago. But I have to admit it seems a lot heavier to carry around and use to engage multiple targets than I remember. Is it that I’ve been spoiled by using lighter weapons such as the M4 or contemporary fighting shotguns or am I just getting older and weaker? It’s probably both!

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About the Author

Leroy Thompson was born in St. Louis, Missouri and has continued to use it as his base of operations, though he has lived overseas at times. He has an undergraduate degree in Business Administration and graduate degrees in English from St. Louis University and University College London. He has trained military and law enforcement personnel in various countries and has written 53 books and more than 3,000 magazine articles on military, law enforcement, and firearms topics. 

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