The Variants
The "Persuader" and "Annihilator" were both experimental approaches of the Thompson submachine gun design idea. The Persuader was essentially a belt-fed version appearing in 1918 while the Annihilator was a box-fed model fitting the 20- and 30-round box magazines appearing in 1918 and 1919.
Model 1919 saw limited production examples totaling just 40 units. The Model 1919 did not feature a buttstock or front sights and was fully-automatic, utilizing Colt .45 ammunition (though other ammunition types were tested). Its rate-of-fire was listed at an amazing 1,500 rounds-per-minute and was demonstrated to the US Military in 1920 though only some New York City Police sales amounted.
Model 1921 became the first quantitative production model of any Thompson submachine gun totaling some 15,000 examples in all. Rate-of-fire was listed at 800 rounds-per-minute and became a favorite of Prohibition-era gangsters and police forces alike.
Model 1923 was an attempt by Auto-Ordnance to showcase the weapon to the US Army. This model operated with the .45 Remington-Thompson cartridge allowing for more range and better penetration at distance. The Model 1923 also brought along new changes to the Thompson submachine gun family line in that it introduced a bipod, bayonet lug, sling and horizontal forearm. However, by this time, the Browning Automatic Rifle (BAR) was already adopted by the US Army and the Model 1923 would be essentially filling the same role in service. As such, now further thought to adopting the Model 1923 was given.
Model 1927 was based on the M1921 but fitted with an open bolt assembly and offering a semi-automatic fire mode only (conversion to full-automatic mode was simple enough however). The Model M1927A1 (also "Thompson Semi-Automatic Carbine") was a semi-automatic version produced for the civilian market between 1974 and 1999. Production was handled by Kahr Arms of Massachusetts. Auto-Ordnance of West Hurley produced the Model 1927A3, another semi-automatic form but firing a .22 caliber cartridge. The Model 1927A5 became a semi-automatic .45ACP pistol version also produced by Auto-Ordnance. Production is still ongoing.
Model 1928 was the first Thompson submachine gun to achieve widespread use by US military forces consisting of the US Marine Corps and US Navy. The Navy requested that the cyclic rate-of-fire be brought down so Model 1928s were essentially Model 1921s with added weight in the actuator. With the arrival of World War 2 in Europe, the Model 1928 began to see large production orders.
The M1928A1 Thompson (or more specifically as "Submachine Gun, Cal. .45, M1928A1, Thompson") appearing in 1928 operated from a delayed blowback system. These weapons were issued to reconnaissance and armor group elements and featured selective fire settings for semi- or full-automatic modes along with a removable buttstock. Fire selection was via a switch along the left side of the body while the buttstock was removable via two screws along the underside - though the buttstock was generally left on to help in stabilizing aim. Additionally, some were produced without the horizontal foregrip and made with a vertical one instead. The charging handle was fitted to the top of the receiver and cooling fins were apparent along the barrel. The gun was fed via a 20- or 30-round detachable box magazine or a 50-round drum and utilized .45 caliber ammunition. Magazine counts also included a little-known 18-round magazine and a 100-round drum. The rate-of-fire was between 600 and 725 rounds-per-minute. A Cutt's muzzle compensator was added in an attempt to divert gasses upwards and keep the barrel down when firing. This proved of limited value and added more complexity to the build, being left off of later M1928A1 production examples. The M1928A1 maintained a length of 33.75 inches and an unloaded weight of 10lbs, 12oz. The barrel measured at 10.50 inches and sported a 6-groove, right hand twist.
For all intents and purposes, however, the M1928A1 proved much too heavy for the standard infantryman to lug around all day and too expensive to produce in wartime. The 50-drum magazine - while sound in theory - proved to add much unneeded extra weight and made for too much noise when silence was imperative. The M1928A1 was based highly on the Model 1921 before it and entered service from 1928 through 1934. Full-scale production of the type did not begin until 1939 however. A "Navy" model of the M1928A1 existed and this was denoted by the use of a horizontal foregrip, muzzle compensator and swivel slings. Civilian models of the time were noted for their vertical foregrip - then (and now) made more famous by police and gangsters of the 1920s as well as Hollywood icons of the time.
Production of the M1928A1 was handled by Colt's Patent Firearms Manufacturing Corporation in Hartford, Connecticut, and the Savage Arms Company Corporation of Utica, New York, this for the Auto-Ordnance Corporation of Bridgeport Connecticut. M1928A1's saw action with American forces in Nicaragua and were also utilized by the US Coast Guard for a time as well as other home guard and second-line units.
By the time World War 2 came to America's door, the M1928A1 proved too expensive to produce in the large quantities needed. As such, the M1 and M1A1 appeared as relatively inexpensive alternatives to the complicated and expensive M1928A1. Savage Arms Corporation was already manufacturing the M1928A1 at its plant and needed to push more out the door with Lend-Lease orders coming in. As such, the M1 was developed to provide for a better mass-production alternative.
M1 (or "Submachine Gun, Cal. .45, M1 Thompson") was simply a redesign of the expensive M1928A1 models in an effort to simplify and, more importantly, lower production costs. It also featured a simple blowback firing action and offered up modes of fire in semi- and full-automatic. The bolt-handle was moved to the right hand side of the body as opposed to the top of the weapon. The sights were further simplified and the muzzle compensator was removed altogether. A 20- or 30-round detachable box magazine could be used (the 50-round drum was dropped) and the rate-of-fire hovered around 500 rounds-per-minute. Ammunition was the .45 caliber slug. The M1 also featured a permanent buttstock as opposed to the detachable version as found on the M1928A1. The firing pin, however, was as in the M1928A1 and spring-loaded. The rear sight was of a fixed aperture type.
The M1A1 was a slightly revised and improved version of the M1. Its firing pin was now being machined (fixed) to the face of the bolt and replaced the hammer of old essentially making it a "virtual" blowback system. Beyond that, it maintained much of what the M1 a successful weapon. It became the last military Thompson submachine model to be produced.
Small numbers of "European" Tommy Guns were produced by Birmingham Small Arms Company (BSA) of England under the designation of BSA 1926. These appeared in the 7.63 Mauser and 9mm calibers but found very few in the way of purchases.
The Verdict
In combat practice, the M1/M1A1 series proved an overwhelming success. Users noted the weapons reliability in even the most grueling of combat settings and the ability to put much "heat" onto a target was second to none. Its A .45 ACP cartridge proved a more-than-capable manstopper and the handling capabilities were very user-friendly. Though the British Sten series and the M3 "Grease Gun" were both cheaper implements charged with replacing the M1 Thompson, many operators preferred their reliable and older weapon over the new ones being issued. Production of the M1/M1A1 would continue on into 1945. The US military dropped all use of the Thompson in 1971. putting an end to some 33 years of faithful service.
Thompson Nicknames
During her operational days, the M1 Thompson garnered such nicknames as the "Trench Sweeper", "Chicago Piano", "Chicago Typewriter", "The Chopper" and the "Trench Broom". However, it is perhaps known best as the "Tommy Gun".
It should be noted that the Tommy Gun was also utilized by the IRA, acquired via supporters within the United States, and used in the Irish War of Independence (1919 through 1922) and Civil War (1922 through 1923).
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