Auto-Ordnance Company
American firearms company best known for developing and producing the Thompson submachine gun. An American defense contractor.
Last updated October 30, 2026
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Overview
Auto-Ordnance Corporation is an American firearms company whose historical importance rests primarily on the Thompson submachine gun. The company was established in August 1916 by retired United States Army Ordnance Department colonel John T. Thompson, with financial backing from investor Thomas Ryan. Thompson had become interested in Commander John Blish's patented delayed-blowback principle and obtained rights to use the patent when the company was formed. He recruited engineers Theodore H. Eickhoff and Oscar V. Payne to investigate whether the mechanism could support a practical automatic rifle or other military arm. The early engineering program initially pursued a rifle-caliber automatic weapon. Testing showed that the Blish system was not suitable for the .30-06 rifle cartridge in the intended form, but worked effectively with the lower-pressure .45 ACP pistol cartridge. Thompson consequently redirected the project toward a compact, high-volume-fire weapon intended for close combat. He described the concept in terms such as a trench sweeper or trench broom, reflecting the First World War environment in which the weapon was conceived. The first limited production model appeared in 1919, after the end of the war, preventing the original design from fulfilling its intended wartime role. The Thompson was initially manufactured for Auto-Ordnance by Colt rather than in an Auto-Ordnance-owned factory. The Model 1921 became the first commercially significant version, although its high cost and distinctive appearance limited early sales. The weapon found customers among law-enforcement agencies and private users before achieving broad military adoption. Its association with Prohibition-era criminals and the American press helped establish the popular nickname Tommy Gun, while the weapon's later service with Allied forces during the Second World War gave it a durable military reputation. During the 1920s Auto-Ordnance also developed prototypes for military rifle competitions and participated in .30-caliber carbine trials. These projects did not result in the adoption of an Auto-Ordnance design. The company's most important production period came during the Second World War, when it established a plant in Bridgeport, Connecticut. There it produced M1928A1, M1, and M1A1 Thompsons to supplement output from Savage Arms. Auto-Ordnance also manufactured components for other military firearms as a subcontractor. The Thompson M1A1 was especially associated with vehicle crews and other users who valued compactness and firepower, although its considerable weight and limited effective range restricted its role. The original company's assets were acquired by Numrich Arms Corporation in the 1950s, an entity unrelated to the original Auto-Ordnance. Numrich assembled a limited number of Thompson submachine guns from receivers acquired in 1951, mainly for law enforcement, and supplied replacement parts to agencies and collectors. In the 1970s the Numrich-era business produced a small number of fully automatic Thompsons and a larger variety of semiautomatic replicas, including .22-caliber versions, for the collector market. In 1999 Auto-Ordnance was acquired by Saelio Enterprises, the parent company of Kahr Arms. Under Kahr ownership the brand operates primarily as a producer of semiautomatic Thompson-style firearms rather than original selective-fire military submachine guns. Its modern products include .45 ACP carbines and pistols styled after historical Thompson variants, as well as reproductions of the M1 carbine and M1911 pistol. Modern semiautomatic Thompsons differ internally from the original open-bolt selective-fire weapons and incorporate design changes intended to prevent conversion using original full-automatic parts. The brand thus combines historical firearms recognition with a contemporary collector, sporting, and civilian-market business model.
History
Auto-Ordnance was founded in August 1916 by John T. Thompson, a retired United States Army Ordnance Department colonel, with financial support from Thomas Ryan. Thompson's interest in automatic weapons had been reinforced by his discovery of the Blish lock patent in 1915. The company obtained rights connected with the patent and hired Theodore H. Eickhoff and Oscar V. Payne to lead its engineering work. The original program sought to develop an automatic rifle. Engineers found that the delayed-blowback principle did not perform effectively with the .30-06 rifle cartridge, but it was well suited to the .45 ACP pistol cartridge. Thompson then conceived a compact automatic weapon intended for close-range combat and promoted it as a trench sweeper or trench broom. The first short production run appeared in 1919, too late for service in the First World War. The initial Model 1921 production was undertaken by Colt. Although the weapon was not immediately adopted on a large military scale, it attracted law-enforcement and civilian attention. Its use and depiction during the Prohibition era made the Thompson a widely recognized gangster weapon, while later military use transformed its public image into that of a major Allied wartime arm. Auto-Ordnance pursued additional designs during the 1920s, including prototypes submitted for military rifle trials. The company also produced designs for .30-caliber carbine trials in the early 1940s, but these efforts were not adopted by the military. The Second World War nevertheless brought substantial production activity. Auto-Ordnance established a Bridgeport, Connecticut, plant and manufactured M1928A1, M1, and M1A1 variants, supplementing production by Savage Arms. It also served as a subcontractor for components used in other military firearms. The M1A1 was commonly associated with tank crews and other vehicle-related personnel because of its compactness relative to a rifle, although the weapon's heavy weight and short effective range limited its general-purpose utility. Its volume of fire and stopping power also contributed to its use in urban and jungle combat. The original Auto-Ordnance company's assets passed to Numrich Arms Corporation during the 1950s. Numrich was not the same entity as the 1916 company. It assembled limited numbers of Thompson guns from receivers acquired in 1951, mainly for law-enforcement customers, and became an important supplier of Thompson parts to agencies and collectors. In the 1970s, the Numrich-era Auto-Ordnance business made a small number of fully automatic guns and many semiautomatic replicas, including .22 LR versions, targeting the collector market. Saelio Enterprises Inc., the parent company of Kahr Arms, acquired Auto-Ordnance in 1999. Kahr continued the brand as a modern manufacturer of semiautomatic Thompson-pattern firearms. Current-era designs have included the 1927A-1 Chicago Typewriter-style carbine, the Commando-style model, the TM1 modeled on the later M1 configuration, and a Thompson pistol without a conventional shoulder stock. These firearms resemble historical Thompsons but are mechanically distinct from the original selective-fire guns: modern semiautomatic versions use a closed-bolt system, and dimensional changes are intended to prevent the installation of original full-automatic bolts and fire-control components. The brand has also produced reproductions of the M1 carbine and M1911 pistol, extending its historical-reproduction portfolio beyond the Thompson family.
- 1999
Kahr parent acquires Auto-Ordnance
[1]Saelio Enterprises acquires the brand and continues its semiautomatic historical-reproduction business.
- 1974
Collector-oriented replicas expand
[1]The Numrich-era business produces semiautomatic Thompson reproductions and a limited number of fully automatic examples.
- 1951
Numrich acquires company assets
[1]Numrich Arms acquires assets of the original Auto-Ordnance business and later supports production and parts supply.
- 1940
Bridgeport wartime plant opens
[1]Auto-Ordnance establishes its own Bridgeport, Connecticut, production facility during the Second World War.
- 1921
Model 1921 production begins
[1]Colt manufactures the first significant production version of the Thompson for Auto-Ordnance.
- 1919
First Thompson production run
[1]A limited production model is completed after the First World War, preventing the original weapon from seeing the conflict for which it was conceived.
- 1916
Auto-Ordnance is founded
[1]John T. Thompson establishes Auto-Ordnance in August with backing from Thomas Ryan to develop automatic firearms.
Products and positioning
A heritage firearms brand centered on the Thompson platform, combining historic military and law-enforcement associations with semiautomatic reproductions for collectors and civilian firearm users.
Submachine gun · 1919
Thompson submachine gun
The Thompson is Auto-Ordnance's defining product. Developed from work on the Blish operating principle and chambered for .45 ACP, it was conceived as a compact automatic weapon for close combat. Early Model 1921 guns were manufactured by Colt, while later M1928A1, M1, and M1A1 versions were produced by Auto-Ordnance and Savage Arms during the Second World War. The design became associated both with Prohibition-era criminal violence and with Allied military service.
Semiautomatic Thompson carbine
1927A-1 Chicago Typewriter
A semiautomatic civilian-market reproduction styled after the Model 1921 Thompson associated with the gangster era. It preserves the recognizable external character of the historical platform while operating as a semiautomatic firearm rather than an original selective-fire submachine gun.
Semiautomatic Thompson carbine
1927A-1 Commando
A semiautomatic reproduction modeled on early Second World War-era Thompson styling, including the visual treatment associated with the M1928A1 and its Cutts compensator. It is positioned as a historical-pattern civilian firearm.
Semiautomatic Thompson carbine
TM1
A semiautomatic Thompson-pattern firearm modeled on the later M1 configuration. Its styling includes the side-mounted charging handle associated with the wartime M1 Thompson, while its modern internal design distinguishes it from the original open-bolt military weapon.
Semiautomatic pistol
Thompson pistol
A semiautomatic Thompson-pattern firearm based visually on the M1928 family but configured without provision for a shoulder stock. It extends the Thompson reproduction concept into a pistol-format product for the civilian and collector market.
Historical firearm reproduction
M1 carbine reproductions
Auto-Ordnance has also produced reproductions of the U.S. M1 carbine, broadening its portfolio from the Thompson platform to other recognizable American military small arms.
Historical firearm reproduction
M1911 pistol reproductions
The brand's historical-reproduction range includes M1911-style pistols, linking Auto-Ordnance's modern product portfolio to another prominent American service firearm.
Brand decisions
1999
Join the Kahr corporate groupM&ABackground
Auto-Ordnance had operated through the Numrich Arms successor business and had developed a collector-oriented reproduction market.
Action taken
Saelio Enterprises, the parent company of Kahr Arms, acquired Auto-Ordnance.
Aftermath
The brand continued with semiautomatic Thompson-style firearms and related historical reproductions rather than returning to its original selective-fire military production model.
1940
Establish an in-house wartime production plantStrategyBackground
Second World War demand required additional Thompson production beyond the capacity supplied by outside manufacturers such as Savage Arms.
Action taken
Auto-Ordnance opened a manufacturing facility in Bridgeport, Connecticut, to produce wartime Thompson variants and firearm components.
Aftermath
The company became a direct wartime producer of M1928A1, M1, and M1A1 Thompsons and a subcontractor for other military firearms.
1916
Redirect development from an automatic rifle to a .45 ACP close-combat weaponStrategyBackground
Engineering tests indicated that the Blish operating principle was ineffective with the .30-06 rifle cartridge but workable with the .45 ACP pistol cartridge.
Action taken
Auto-Ordnance shifted its principal development effort toward a compact, high-volume-fire weapon intended for close combat, leading to the Thompson design.
Aftermath
The decision created the product platform that became the company's defining firearm, although the first production model arrived after the First World War.
Recent events
- 1999
Auto-Ordnance is acquired by Saelio Enterprises[1]
M&A
Saelio Enterprises, the parent company of Kahr Arms, acquired Auto-Ordnance and continued the brand's production of semiautomatic Thompson-style firearms.
- 1974
Auto-Ordnance develops semiautomatic Thompson reproductions[1]
Product launch
The Numrich-era business produced a small number of fully automatic Thompsons and numerous semiautomatic replicas, including .22 LR models, for collectors.
- 1951
Auto-Ordnance assets are acquired by Numrich Arms[1]
M&A
Numrich Arms acquired assets of the original company and later used receivers from the transaction to assemble limited Thompson quantities and support the parts market.
- 1940
Auto-Ordnance expands wartime Thompson production[1]
Product generation
During the Second World War, the company established production in Bridgeport, Connecticut, making M1928A1, M1, and M1A1 Thompsons and parts for other military firearms.
- 1921
Colt begins production of the Model 1921 Thompson[1]
Product generation · Product launch
Colt manufactured the initial production Model 1921 Thompson for Auto-Ordnance, establishing the platform's commercial identity.
- 1919
The Thompson enters limited production[1]
Product launch
The first short production run of the Thompson design was completed after the First World War had ended.
- 1916
Auto-Ordnance is established to develop automatic firearms[1]
Other
Retired Colonel John T. Thompson founded Auto-Ordnance with investor Thomas Ryan and began development work based on the Blish patent.
Sources2 sources
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