Guns, Weapons & FireArms

Early versions of the Thompson had a fairly high rate of fire, approaching 800-850 rounds per minute. Later M1 and M1A1 Thompsons averaged 600 rpm. This rate of fire, combined with a rather heavy trigger pull and a stock with excessive drop, increases the tendency of the gun to climb off target in automatic fire. Compared to modern 9mm sub machine guns, the .45 Thompson is quite heavy. This was one of the major complaints against the weapon made by service members of militaries that issued the Thompson.

While the drum magazine provided significant firepower, in military service it was found to be overly heavy and bulky, especially when slung on patrol or on the march. For this reason, the 20-round and later 30-round box magazines soon proved most popular with military users, and drum compatibility was eliminated from the wartime M1 and M1A1 models. The Thompson was one of the earliest sub machine guns to incorporate a double-column, double-feed box magazine design, which undoubtedly contributed to the gun's reputation for reliability. In addition, the gun performed better than most after exposure to rain, dirt, and mud.

Because of its gangster-era and World War II connections, Thompsons are highly sought as collector's items. An original Model 1928 in working condition can easily fetch US$20,000 or more. Approximately 1,700,000 of these weapons were produced by Auto-Ordnance, Savage Arms, and Colt, with 1,387,134 being the simplified World War II M1 and M1A1 variants (without the Blish lock and oiling system). Semi-automatic versions configured as civilian-legal rifles are currently produced by Auto-Ordnance Company, a division of Kahr Arms, for the collector market at prices ($900.00 to $1400.00) considerably lower than the prices for originals.

Types

Persuader and Annihilator

There were two main experimental models of the Thompson. The Persuader was a belt-fed version developed in 1918, and the Annihilator was fed from a 20 or 30-round box magazine, which was an improved model developed in 1918 and 1919. Additionally, the 50- and 100-round drum magazines were developed.

Model of 1919

The Model of 1919 was limited to about 40 units, with many variations noted throughout. The weapons had very high cyclic rates around 1,500 rpm. This was the weapon Brigadier General Thompson demonstrated at Camp Perry in 1920. Almost all Model of 1919s were made without buttstocks and front sights, and the final version closely resembled the later Model of 1921. The New York City Police Department was the largest purchaser of the Model of 1919. This model was designed as an automatic Colt .45 to "sweep" trenches with bullets. Some experimental calibers were .45ACP (11.4x23mm), .22LR, .32 ACP, .38 ACP, and 9mmP.

Model of 1921

The Model of 1921 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 a blued, finned barrel and vertical foregrip and the Blish lock. The Model of 1921 was quite expensive to manufacture, with the original retail cost around $225, because of its high quality wood furniture and finely-machined parts. The Model of 1921 was famous throughout its career with police and criminals and in motion pictures. The weapon had a relatively high 800+ rpm rate of fire.

Model of 1923

The Model of 1923 was introduced to potentially expand the Auto-Ordnance product line and was demonstrated for the U.S. Army. It fired the .45 Remington-Thompson cartridge from a 14-inch (35.5 cm) barrel, with greater range and power than the .45 ACP. It introduced a horizontal forearm, sling, bipod and bayonet lug. The M1923 was intended to fill the role of the Browning Automatic Rifle (BAR), but the Army was satisfied with the BAR and did not give the Model of 1923 much consideration, so it was not adopted.

BSA Thompsons

In an attempt to expand interest and sales overseas, Auto-Ordnance partnered with and licensed Birmingham Small Arms Company (BSA) in England to produce a European model. These were produced in small quantities and have a different appearance than the classic style. The BSA 1926 was manufactured in 9 mm and 7.63 Mauser calibre and were tested by various governments, including France in the mid 1920s. It was never adopted by any military force, and only a small number were produced.

Model of 1927

The Model of 1927 was the semi-automatic-only version of the M1921. It was made by modifying an existing Model of 1921, including replacing certain parts. The "Thompson Sub machine Gun" inscription was machined over to replace it with "Thompson Semi-Automatic Carbine", and the "Model of 1921" inscription was also machined over to replace it with "Model of 1927." Although the Model of 1927 was semi-automatic only, it was easily converted to fully automatic by utilizing a Model of 1921 receiver, and is classified as a machine gun under the National Firearms Act of 1934.

Model of 1928

The Model of 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 of 1928s were Model of 1921s with weight added to the actuator, which slowed down the cyclic rate of fire, a U.S. Navy requirement. With the start of World War II, major contracts from Britain and France saved the manufacturer from bankruptcy.

M1928A1

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. 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. The weapon was mostly used in the U.S. military by the Marine units in the Pacific Theater. Though it could use both the 50-round drum and the 20- or 30-round box magazines, active service showed the drums were more prone to jamming, rattled when moving, and extremely heavy and bulky, especially on long patrols. 562,511 were made. Wartime production variants had a fixed rear sight with out the triangular sight guard wings and a non-ribbed barrel both like that found on the M1/M1A1.

In addition, the Soviet Union received M1928A1s, included as standard equipment with the M3 light tanks obtained through Lend-Lease. The weapons were never issued to the Red Army, however, because of a lack of .45 ACP ammunition on the Eastern Front, and were simply put in storage. As of September 2006, limited numbers of these weapons have been re-imported from Russia to the United States as disassembled "spare parts kits", the entire weapon less the receiver (as required by Federal law).

M1

Answering the call for further simplification, the M1 was standardized in April 1942 as the United States Sub machine Gun, Cal. .45, M1. Rate of fire was reduced to approximately 600-700 rpm. First issued in 1943, the M1 utilized a simple blow back operation, the charging handle was moved to the side, and the flip-up adjustable rear sight replaced with a fixed aperture (peep sight). Wartime production variants omitted the triangular rear sight guard wings. The slots adjoining the magazine well allowing use of the drum magazine were removed. The less expensive and more-easily manufactured "stick" magazines were used exclusively in the M1, with a new 30-round version joining the familiar 20-round type. The Cutts compensator, barrel cooling fins, and Blish lock were omitted while the buttstock was permanently affixed.

M1A1

The M1A1, formally adopted as the United States Sub machine Gun, Cal. .45, M1A1, could be produced in half the time of the M1928A1, and at a much lower cost. The multi-piece firing pin of the M1 was supplanted by a simplified firing pin machined into the face of the bolt. The 30-round magazine became more common. In 1939, Thompsons cost the government $209 apiece. By the spring of 1942, cost reduction design changes had brought this down to $70. In February 1944, the M1A1 reached a low price of $45 each, including accessories and spare parts. By the end of 1944, the M1A1 was replaced with the even lower-cost M3 (commonly called "Grease Gun").

Model 1927A1

The Model 1927A1 is a semi-automatic only version of the Thompson, originally produced by Auto-Ordnance (West Hurley, New York) for the civilian gun market from 1974 to 1999. It is officially known as the "Thompson Semi-Automatic Carbine, Model of 1927A1." The internal design is completely different and operates from the closed bolt, hence is legal for civilian ownership in the United States without a special license. It has been produced since 1999 by Kahr Arms of Worcester, Massachusetts. This weapon should not be confused with the earlier Model of 1927 produced by Colt for Auto-Ordnance, although its name and designation references the earlier semi-automatic model. The Model 1927A1 is the semi-automatic replica of the Thompson Models of 1921 and 1928; the Auto-Ordnance replica of the Thompson M1 and M1A1 is known as the TM1 and may be found marked "Thompson Semi-Automatic Carbine, Caliber .45M1".

Model 1927A3

The Model 1927A3 is a semi-automatic, .22 caliber version of the Thompson produced by Auto-Ordnance in West Hurley.

Model 1927A5

The Model 1927A5 is a semi-automatic pistol version, .45ACP version of the Thompson originally produced by Auto-Ordnance in West Hurley. It featured an aluminum receiver to reduce weight. It has been produced since 2008 by Kahr Arms of Worcester, Massachusetts as the "M1927A1 TA5".


Specifications

Weight: 10.8 lb (4.9 kg) empty (M1928A1)
10.6 lb (4.8 kg) empty (M1A1)
Length: 33.5 in (851 mm) (M1918A1)
32 in (813 mm) (M1/A1)
barrel: 10.5 in (267 mm)
barrel with optional Cutts Compensator: 12 in (305 mm)
Cartridge: .45 ACP (11.43 × 23 mm)
Action: Blowback
Rate of fire: 600-1200 rpm, depending upon model
Muzzle velocity: 920 ft/s (280 m/s)
Feed system: 20-round Type XX box magazine
30-round Type XXX box magazine
50-round Type L drum magazine
100-round Type C drum magazine
(M1 and M1A1 models do not accept drum magazines)