Editing Thompson submachine gun (section)

===Production===
====Model 1921====
[[File:Thompson 1921 submachine gun.jpg|thumb|Thompson Model 1921.]]
The Model 1921 (M1921) was the first major production model. Fifteen thousand were produced by Colt for Auto-Ordnance. In its original design, it was finished more like a sporting weapon, with an adjustable rear sight, a blued, finned barrel and vertical [[foregrip]] (or pistol grip) and the Blish lock. The M1921 was quite expensive to manufacture, with the original retail price around $200, because of its high-quality wood furniture and finely [[machined]] parts. The M1921 was famous throughout its career with police and criminals and in motion pictures. This model gained fame from its use by criminals during Prohibition, and was nicknamed "Tommy gun" by the media.<ref>{{cite news |last1=Johnson |first1=Cara |title='The Gun That Made The '20s Roar': Inside The Blood-Soaked History Of The Infamous Tommy Gun |url=https://allthatsinteresting.com/tommy-gun |access-date=5 July 2022 |work=All That's Interesting |date=27 June 2022}}</ref>

====Model 1923====
The Model 1923 was a heavy submachine gun introduced to potentially expand the Auto-Ordnance product line and was demonstrated for the U.S. Army. It fired the more powerful [[.45 Remington–Thompson]] [[Cartridge (firearms)|cartridge]] which fired a heavier {{convert|250|gr|oz g|abbr=on|lk=on}} bullet at muzzle velocities of about {{convert|1,450|ft/s|m/s|abbr=on}} and energy about {{convert|1170|ftlb|J|abbr=on|lk=on}}, with greater range than the .45 ACP. It introduced a horizontal [[Forearm (firearm component)|forearm]], improved inline stock for accuracy, {{convert|14|in|cm|abbr=on}} barrel, [[bipod]], and [[bayonet]] lug. The M1923 was intended to rival the [[M1918 Browning Automatic Rifle]] (BAR), with which the Army was already satisfied. The Army did not give the Model 1923 much consideration, so it was not adopted. In addition to the .45 Remington–Thompson, the M1923 Thompsons were to be made available to prospective buyers in several calibers, including [[.45 ACP]], [[9mm Parabellum]], [[9mm Mauser]], and [[.351 Winchester]] Self-loading.<ref>Small Arms Review, Vol. 26, No. 5, p. 35</ref>

====Model 1921AC (1926)====
While not a new model in the usual sense of incorporating major changes, in 1926 the Cutts Compensator (a [[muzzle brake]]) was offered as an option for the M1921; Thompsons with the compensator were cataloged as No. 21AC at the original price of $200.00, with the plain M1921 designated No. 21A at a reduced price of $175.00.<ref name="Frank Iannamico 1928"/> The Model 1921 was thereafter referred to as Model 1921A or Model 1921AC, though some collectors still refer to it as the Model 1921.

====Model 1928====
[[File:Thompson submachine gun at Alcatraz.jpg|thumb|left|A deactivated M1928 Thompson submachine gun at Alcatraz, San Francisco Bay.]]

The Model 1928 was the first type widely used by military forces, with the U.S. Navy and U.S. Marine Corps as major buyers through the 1930s. The original Model 1928s were Model 1921s with weight added to the actuator, which slowed down the [[cyclic rate]] of fire, a United States Navy requirement. On these guns, the model number "1921" on the receiver was updated by stamping an "8" over the last "1". The Navy Model 1928 has several names among collectors: the "Colt Overstamp", "1921 Overstamp", "28 Navy", or just "28N".

The 1928 Thompson would be the last small arm adopted by the U.S. Army that used a year designation in the official nomenclature. With the start of World War II, major contracts from several countries saved the manufacturer from [[bankruptcy]]. A notable variant of the Model 1928 with an aluminum receiver and tenite grip, buttstock, and forend, was made by Savage.<ref>{{cite web |url=http://www.machinegunbooks.com/eleven.html |title=Thompson Gallery |publisher=www.MachineGunBooks.com |access-date=2011-12-25 |archive-date=2013-01-04 |archive-url=https://web.archive.org/web/20130104121826/http://www.machinegunbooks.com/eleven.html |url-status=dead }}</ref>

====M1928A1====
[[File:Halftrack-fort-knox-4.jpg|thumb|M1928A1 at [[Fort Knox, Kentucky|Fort Knox]], [[Kentucky]], June 1942]]

The M1928A1 variant entered mass production before the [[attack on Pearl Harbor]], as on-hand stocks ran out. Changes included a horizontal forend, in place of the distinctive vertical foregrip ("[[pistol grip]]"), and a provision for a military [[sling (firearms)|sling]]. Despite new U.S. contracts for Lend-Lease shipments abroad to China, France, and the United Kingdom, as well as the needs of American armed forces, only two factories supplied M1928A1 Thompsons during the early years of World War II. Though it could use both the 50-round drum and the 20- or 30-round box magazines, active service favored the box magazines as the drums were more prone to jamming, rattled when moving, and were too heavy and bulky on long patrols. 562,511 were made. Wartime production variants had a fixed rear sight without the triangular sight guard wings and a non-ribbed barrel, both like those found on the M1/M1A1.

In addition, the Soviet Union received M1928A1s, included as standard equipment with the [[M3 Stuart|M3]] [[light tank]]s obtained through Lend-Lease. These submachine guns were used to a limited extent by the Red Army.<ref>{{cite web|url=https://pamyat-naroda.ru/documents/view/?id=238922686|title = Память народа::Поиск документов частей}}</ref>

Some M1928A1 Thompsons were used by the French before and during the Battle of France (1940) under the designation "Pistolet-mitrailleur 11 mm 43 (C.45) M. 28 A1."

An M1928A1 with an unusual inline stock, modified with elevated sights to increase accuracy, also was produced. Some Thompsons were built with a folding stock, similar to [[M1A1 Carbine]]s used by Allied tank crews, drivers and paratroopers and submarine raiders.<ref>{{cite web|url=http://www.forgottenweapons.com/experimental-thompson-stock/|title=Experimental Thompson Stock|work=Forgotten Weapons|date=2012-12-07}}</ref>