Thompson M1928A1 .45” sub machine gun

01. Original name Thompson M1928A1 .45” Sub Machine Gun   
02. Other official names Thompson Submachine Gun, Caliber .45; Submachine Gun, Caliber .45 M1928A1  
03. Popular names Thompson, Chicago Piano, Chicago Typewriter, Tommy Gun, Trench Broom, Trench Sweeper, The Chopper  
04. Chamberings .45 ACP 10mm Auto  
05. Designed by John T Thompson  
06. Design date 1918  
07. In service date(s) 1921 onwards (US Navy in 1928, USMC in 1930, US Army in 1938, UK in 1940)  
08. Adopted by Over fifty countries, including the USA, UK and the Commonwealth  
09. Production quantities 562,511 (out of around 1.75 million of all variants)  
10. Mechanism Blowback utilising the Blish Lock, loaded with either box (twenty or thirty rounds) or drum (fifty or 100 rounds) magazines  
11. Weight 10.8lbs (4.9kg) unloaded  
12. Mountings Sling  
13. Practicality in action Medium-to-High – relatively compact fully automatic weapon useful for close quarters combat, balanced by issues with weight and accuracy over fifty yards  
14. Comments / Other information The M1928A1 was a development of the earlier M1921, designed by John T. Thompson and produced initially by Auto Ordnance Company (AOC). The weapon sold in small quantities on the civilian market, to local and federal law enforcement agencies as well as to the US Marine Corps. It’s use by those involved in organised crime (‘gangsters’) such as Al Capone, John Dillinger and ‘Machine Gun’ Kelly brought it a certain notoriety, as did the later Hollywood portrayal of the ‘Roaring Twenties’. The main differences between the M1921 and M1928 is that the latter had the Cutts Compensator and barrel cooling fins, while the main difference between the M1928 and M1928A1 was the latter had a lower rate of fire and horizontal foregrip. During World War II, the design was simplified even further with the M1 and M1A1 versions.. Later version of a gun introduced in 1921; chambered for the .45” ACP round; uses a 50-round vertical drum magazine or 20-round and 30-round box magazines: cyclic rate about 675rpm, weight without magazine 10.75lb; used by Allied forces in WW2; the 1921 model was popular with US Gangsters.