Few firearms have earned the mystique that the Thompson submachine gun has enjoyed for nearly a century. The long association that the “Tommy Gun” has had with gangsters, G-men and G.I.s has made it a movie star, a prized collectible, and an American icon.
The gun’s genesis dates back to World War I when retired General John T. Thompson sought to develop a lightweight, fast-firing rifle that U.S. troops could use as a “trench broom” to break the stalemate of trench warfare.
Thompson believed recoil or gas operated weapons were too heavy and complicated for this role and sought a new method of operation. He formed the Auto-Ordnance Company (AOC), found financial backing, and hired engineers to help develop this weapon.
Thompson seized upon the concept of the Blish Lock, developed by John Bell Blish (a career U.S. naval officer and inventor), as the key element for the design.
The principle is that dissimilar materials adhere to each other on an inclined plane with greater force than similar materials. When work revealed that the .30-06 cartridge was too powerful for this system, the weapon was designed around the standard .45 ACP pistol round instead. In the final design, an H-shaped bronze wedge would adhere to the steel bolt to keep the breech closed until pressure dropped to a safe level.
The resulting weapon was dubbed the Annihilator I. This initial offering resembled later versions of the Thompson SMG, except that instead of a buttstock, it had only rear and forward pistol grips. The distinctive drum magazine also appeared for the first time. However, by the time the prototypes were ready, the war was over, and Auto-Ordnance now had to figure out how to sell a gun designed and produced for a war that had just ended.
They added a buttstock, made some minor mechanical improvements, and rechristened the weapon the “Thompson Submachine Gun.” This was the first use of what would become the standard term for a hand-held, full-auto weapon firing pistol caliber ammunition.
COLT’S MANUFACTURING COMPANY produced the Model 1921 for AOC under contract. The guns were finely machined, with rich bluing, finished walnut stocks and fully adjustable Lyman rear sights. The bolt handle was on the top of the receiver and the separate safety and selector, as well as the magazine release, were on the left side. A Model 1921 weighed almost 11 pounds unloaded and almost 15 pounds with a loaded 50 round drum magazine.
The 10 ½-inch barrel included machined cooling fins. In 1926, designers added a Cutts compensator as an option, and guns so equipped were called the Model 1921AC. The gun fired 230-grain .45 ACP cartridges at a cyclic rate of 800 to 900 RPM. The guns cost $225 each, with a 20-round stick mag. Optional 50-round “L” mags were available for $20 each. To give an idea of the relative expense at that time, a new Model T automobile could be purchased for about $400.
Needless to say, sales were slow. The U.S. Postal Service purchased some for the U.S. Marines to use to guard mail cars on trains. The Marines liked the gun and bought a few hundred more, and they used them to great effect in the South American “Banana Wars” of the 1920s.
The U.S. Army tested the gun, and although they found it suitable, they failed to adopt it. About 650 were sold to the Irish Republic, although U.S. Customs confiscated most of these. An estimated 150 or so did make it to the Irish Republican Army to be used in the Irish Revolution and Irish Civil War.
Auto-Ordnance sold a few guns to police agencies and to large companies worried about labor unrest. In the summer of 1921, several Model 1921s were used in West Virginia’s “Battle of Blair Mountain,” a labor dispute that escalated into an armed conflict between coal miners, the company (who used the Thompson guns), and the government.
This conflict is one of the first recorded uses of the Thompson SMG in action. However, many of the 15,000 Model 1921s manufactured by Colt remained unsold for up to two decades. In 1928 the U.S. Navy placed an order for Thompsons specifically modified to better suit their needs. The changes included a slower rate of fire and a horizontal foregrip.
Auto-Ordnance reduced the ROF to 600 to 700 RPM by adding weight to the bolt with a heavier actuator. The horizontal foregrips were installed (vertical foregrips remained an option on commercial guns) and the modified guns were remarked with an “8” stamped over the “1” in the last digit of “1921.” For that reason, collectors refer to these guns as “Model 1921/1928 Overstamp.”
DESPITE ITS MILITARY INTENT, the Tommy Gun really entered the public consciousness as a crime gun. As Prohibition-era bootleggers and gangsters sought to expand their business, protect their turf and “rub out” the competition, the Thompson was prized for its firepower and large ammo capacity.
Many shooters removed the buttstock to make the gun easier to conceal, although at a loss of accuracy. The negative perception of the Tommy Gun only worsened with the activity of Depression era criminals such as John Dillinger, “Machine Gun” Kelly and “Pretty Boy” Floyd.
High profile killings such as the February 1929 St. Valentine’s Day Massacre, in which seven men were machine-gunned in a Chicago garage, also damaged (or added to) the gun’s reputation. However, as criminals turned to the Thompson, so did the police. Many local agencies acquired Thompsons in case any state hopping “motor bandits” showed in their area.
The FBI also purchased large numbers of the Model 1928 Navy. Ironically, in some cases, these very police guns wound up arming the criminals! During John Dillinger’s famous 1934 escape from the Lake County (Indiana) jail, he stole two Thompsons that had been used by the men who were guarding him. In other cases, criminals raided police stations and National Guard armories to steal the weapons. The hysteria over the Thompson Submachine Gun was enflamed even more by magazine headlines like, “The Amazing Secret Traffic in Gang Death Machines,” and in movies such as 1932’s Scarface, a fictionalized portrayal of Al Capone, which prominently featured a Thompson in the movie poster.
This public fear led to the passage of the National Firearms Act of 1934 that required buyers pay a $200 tax on each machine gun purchase and register the weapon with the Federal government before delivery.
THE START OF WORLD WAR II saved Auto-Ordnance from bankruptcy. As war clouds loomed over Europe in the late 1930s, sales to the French and British brought in much needed cash, and finally exhausted the stock of guns manufactured in 1921. The U.S. Army also belatedly realized it would need more SMGs to fight what would become a global conflict and placed large orders.
Once again, Auto-Ordnance turned to an outside manufacturer to subcontract production. This time it was the Savage Arms Company of Utica, New York (Colt wasn’t interested). As the war progressed, and orders for hundreds of thousands of guns came in, more design changes were made to meet production demands.
The military Model 1928A1 was a simplified version of the Model 1928 Navy. The highly polished blued finish was replaced with a duller blue/black finish. Other small changes included the elimination of the complex Lyman rear sight with a simple stamped “L” sight, elimination of the checkering on small parts, and elimination of the barrel cooling fins.
This was the last version that could accept a drum magazine. However, even with the changes to the Model 1928, the Thompson remained expensive and slow to produce. In a new effort to speed manufacture, Savage simplified the weapon even more. The most significant change was the elimination of the Blish Lock in favor of a straight blow back design with a cyclic rate of about 600 to 650 RPM.
Savage also eliminated the receiver cuts needed to accept the drum magazines, modified the bolt, relocated the bolt actuator to the side of the receiver, and deleted the Cutts compensator. The blued finish was replaced with Parkerization and the buttstock was permanently attached.
These modifications did speed up production and also saved the government about half of the previous $209 cost per gun. A later variant, the M1A1, eliminated the separate firing pin in favor of a pin machined on the bolt face and added protective wings for the rear sight.
The Thompson, in both 1928 and M1 variants, served in all the theaters of the war and afterward, when it was supplied as part of the lend lease program to wartime allies such as the United Kingdom, the Soviet Union and China. It was especially prized for close-in fighting.
By the time the Thompson was replaced on the production lines by the cheaper M3 “Grease Gun” in February 1944, more than 1,750,000 had been manufactured, and these saw service until the end of the war.
Following World War II, the Thompson was largely withdrawn from U.S. service in favor of the M3 and full-auto M2 Carbine. U.S. forces in Korea faced Thompsons in enemy hands, which were originally provided to the Nationalist Chinese but which were incorporated into the Chinese Red Army stocks after Mao took over the country.
In turn, many G.I.s pressed recaptured Thompsons back into service. During the Vietnam War, Thompsons were supplied to South Vietnamese forces as military aid. Although production of the original Thompsons ended in 1944, the Auto-Ordnance Company (under different ownership) briefly made new production full-auto guns in the 1970s and early 1980s. The current company makes semi-auto-only versions today.
The Thompson remains one of the most collectable full-auto firearms,
with prices ranging from $15,000 for a 1970s production gun up to $45,000 or more for a Model 1921 or Model 1928. For most of us, the closest we’ll get to a Thompson is at the movies where the gangster and G.I. guns play a role on the big screen. In 2009, Johnny Depp wielded a Model 1921AC Thompson as bank robber John Dillinger, and who can forget Tom Hanks as Capt. John Miller with his M1A1 Thompson in 1998’s Saving Private Ryan? Although long out of production, the legend of the Thompson lives on.
Story and photos by Rob Reed