Thompson submachine gun


The Thompson submachine gun is a blowback-operated, selective-fire submachine gun, invented and developed by Brigadier General John T. Thompson, a United States Army officer, in 1918. It was designed to break the stalemate of trench warfare of World War I, although early models did not arrive in time for actual combat. The Thompson saw early use by the United States Marine Corps during the Banana Wars, the United States Postal Inspection Service, the Irish Republican Army, the Republic of China, and the FBI following the Kansas City massacre.
The weapon was also sold to the general public. Because it was so widely used by criminals, the Thompson became notorious during the Prohibition era as the signature weapon of various organized crime syndicates in the United States in the 1920s. It was a common sight in the media at the time, and was used by both law enforcement officers and criminals. The Thompson was widely adopted by the U.S. armed forces during World War II, and was also used extensively by other Allied troops during the war. Its main models were designated as the M1928A1, M1, and M1A1 during this time. More than 1.5 million Thompson submachine guns were produced during World War II.
It is the first weapon to be labelled and marketed as a "submachine gun". The original selective-fire Thompson variants are no longer produced, although numerous semi-automatic civilian versions are still being produced by the manufacturer Auto-Ordnance. These models retain a similar appearance to the original models, but have various modifications in order to comply with US firearm laws.

History and service

Development

, who spent most of his career in the ordnance department of the U.S. Army, was the original inventor and developer of the Thompson submachine gun. He envisioned it as a fully automatic rifle intended to replace the bolt-action service rifles then in use.
Thompson came across a patent issued to the American inventor John Bell Blish in 1915, while searching for a way to allow his weapon to operate safely without the complexity of a recoil or gas-operated reloading mechanism. Blish's design was based on the supposed adhesion of inclined metal surfaces under pressure. Thompson gained financial backing from the businessman Thomas F. Ryan and proceeded to found a company, which he named the Auto-Ordnance Company, in 1916, for the purpose of developing his new "auto rifle".
The Thompson was primarily developed in Cleveland, Ohio. Its principal designers were Theodore H. Eickhoff, Oscar V. Payne, and George E. Goll. By late 1917, the limits of the Blish lock were discovered, and, rather than the firearm working as a locked breech, the weapon was instead designed to function as a friction-delayed blowback action. It was found that the only cartridge then in service suitable for use with the new lock was the.45 ACP. General Thompson envisioned a "one-man, hand-held machine gun" chambered in.45 ACP to be used as a "trench broom" for the ongoing trench warfare of World War I. Oscar V. Payne designed the new firearm along with its stick and drum magazines. The project was titled "Annihilator I". Most of the design issues had been resolved by 1918; however, the war ended two days before prototypes could be shipped to Europe.
At an Auto-Ordnance board meeting in 1919, in order to discuss the marketing of the "Annihilator", with the war now over the weapon was officially renamed the "Thompson Submachine Gun". While other weapons had been developed shortly prior with similar objectives in mind, the Thompson was the first weapon to be labeled and marketed as a "submachine gun". Thompson intended for the weapon to provide a high volume of automatic, man-portable fire for use in trench warfare—a role for which the Browning Automatic Rifle had been determined ill-suited. The concept had already been developed by German troops using their own Bergmann MP 18 in concert with their infiltration tactics tactics.

Early use

The first Thompson entered production as the Model of 1921. It was available to civilians, but, because of the weapon's high price, initially saw poor sales. The Thompson had been priced at $200 in 1921
The major initial complaints concerning the Thompson were its cumbersome weight, its inaccuracy at ranges over, and its lack of penetrating power using the.45 ACP cartridge.
The Thompson was first used in combat in 13 June 1921, when West Virginia state troopers fired on the mountainside near Lick Creek, where striking miners were firing at passing cars. By the time of the Battle of Blair Mountain, 37 had been acquired by the West Virginia state police and 56 were in the hands of coal companies and local law enforcement. The guns were also shipped to various hardware stores in the region.
Some of the first batches of Thompsons were bought by agents of the Irish Republican Army. The first test of the Thompson in Ireland was performed by Irish Republican Army unit commander Tom Barry, of the West Cork Brigade, in the presence of IRA leader Michael Collins. They purchased a total of 653 units, though US customs authorities in New York seized 495 of the units in June 1921. The remainder found their way to the Irish Republican Army by way of Liverpool, England, and were used in the last month of the Irish War of Independence. After a ceasefire called by the British in July 1921, the Irish Republican Army imported more units, which were used in the subsequent Irish Civil War. The Thompson was not found to be very effective in Ireland, having only caused serious casualties in 32 percent of the incidents in which it was used.
During the failed 1924 Estonian coup, Communists used Thompsons in an attempt to storm the Tallinn barracks; meanwhile the defenders used MP 18s. This was possibly the first engagement where submachine guns were used on both sides.
The Thompson achieved early notoriety in the hands of Prohibition and Great Depression-era gangsters and the lawmen who pursued them. It was also depicted in gangster films during this era, most notably regarding the Saint Valentine's Day Massacre. The Thompson guns used in the massacre are still being held by the Berrien County Sheriff's Department. The Thompson has been referred to by one researcher as the "gun that made the twenties roar".
Around 200 Model 1921 Thompsons were sold in 1926 to the United States Postal Inspection Service so they could protect the mail from a spate of robberies. These weapons were loaned to the United States Marine Corps which was, at that time, tasked with guarding mail shipments; this prompted the US Navy to formally test the Thompson. The Navy requested a reduction in the rate of fire. Auto-Ordnance complied, modifying the weapons by adding a substantial amount of mass to the actuator. In 1927 a number of Thompsons would be shipped to Marines in China and Nicaragua. The Navy subsequently ordered 500 guns, designated the Model of 1928.
The Thompson saw popularity as a point-defense weapon for countering ambushes by Nicaraguan guerrillas and led to the creation of four-man fire teams which had as much firepower as a nine-man rifle squad. Federal sales were then followed by sales to police departments in the US, as well as to various international armies and constabulary forces; chiefly in Central and South America.
In 1926, the Cutts compensator was offered as an attachment option for the Thompson. Models with the compensator were cataloged as No. 21AC, at the original price of $200. The plain Thompson was designated No. 21A at a reduced price of $175.
In 1928, Federal Laboratories took over distribution of the weapon from Thompson's Auto-Ordnance Corporation. The new cost was listed as $225 per weapon, with ammunition sold at $5 per 50-round drum and $3 per 20-round magazine.
Thompsons had also been widely used throughout China, where several Chinese warlords and their military factions running various parts of the fragmented country made purchases of the weapon, and subsequently produced many local copies.
Nationalist China acquired a substantial number of Thompson guns for use against Japanese land forces. They began producing copies of the Thompson in small quantities for use by their armies and militias. In the 1930s, Taiyuan Arsenal produced copies of the Thompson for Yan Xishan, the then warlord of Shanxi province.
The FBI had also acquired Thompsons in 1933 following the Kansas City massacre.
A number of these guns were acquired by a construction company in Brazil, after construction of a federal road in Sergipe was disrupted by armed Cangaçeiros in December 1937 who violently opposed any attempts to build roads near their territory.

World War II

In 1938, the Thompson submachine gun was adopted by the U.S. military and was used during World War II.
There were two military types of Thompson submachine gun:
  • The M1928A1, which had provisions for both box and drum magazines, utilized the Cutts muzzle brake, had cooling fins on the barrel, and employed a delayed blowback action with the charging handle on the top of the receiver.
  • The M1 and M1A1, which had provisions for box magazines only, did not have cooling fins on the barrel, had a simplified rear sight, and employed a straight blowback action with the charging handle on the side of the receiver.
Over 1.5 million military Thompson submachine guns were produced during World War II.

Magazine developments

Military users of the M1928A1 units had complaints of the "L" 50-round drum magazine. The British Army criticized "the excessive weight, the rattling sound they made" and shipped thousands back to the U.S. in exchange for 20-round box magazines. The Thompson had to be cocked, bolt retracted, ready to fire, in order to attach the drum magazine. The drum magazine also attached and detached by sliding sideways, which made magazine changes slow and cumbersome. They also created difficulty when clearing a cartridge malfunction. Reloading an empty drum with cartridges was a difficult and involved process in which the 50 rounds would be inserted and then the magazine wound up until a minimum of 9 to 11 loud "clicks" were heard before seating the magazine into the weapon.
In contrast, the "XX" twenty-round box magazine was light and compact. It tended not to rattle, and could be inserted with the bolt safely closed. The box magazine was quickly attached and detached, and was removed downward, making clearing jams easier. The box magazine tripped the bolt open lock when empty, facilitating magazine changes. An empty box was easy to reload with loose rounds. However, users complained that it was limited in capacity. In the field, some soldiers would tape two "XX" magazines together, in what would be known as "jungle style", to quicken magazine changes.
Two alternatives to the "L" 50-round drum and "XX" 20-round box magazines were tested 6 December 1941, at Fort Knox, Kentucky. An extended thirty-round box magazine and a forty-round magazine, which were made by welding two 20-round magazines face to face, jungle style, were tested. The testers considered both superior to either the "XX" box or "L" drum. The 30-round box was approved as the new standard in December 1941 to replace the "XX" and "L" magazines.