The iconic Thompson Machine Gun was first developed in 1919 as a possible replacement for The Browning Automatic Rifle. Seen as a "Trench Weapon ", it was originally named "The Annililator". The ending of World War I did not stop production of the weapon, as a longer and heavier weapon was marketed. The Model 1927, nicknamed "The Tommy Gun", became a popular weapon for Law Enforcement (and criminal alike). A more compact version of designed again for possible purchase by the US Government. This weapon, The Model 1938 began a standard issue weapon among Squad Leaders (NCO), as a rapid fire, close quarters weapon. With Britain's involvement in World War II, thousands were purchased for combat use. With America's eventual involvement, The Thompson was redesignated as The M-1 in 1942. Weighing 16-pounds and being 35-inches in length, The Thompson chambered a .45 caliber round. Blowback operated, the weapon used a 20, 30 and 50 round drum magazine (although this was rarely used in combat). The Thompson had a maximum effective range of 200 meters. Over 2 million were produced for The War effort. The weapon was a popular issue with The US Marines, who relied heavily on The Thompson during The Pacific Islands Campaigns. It was also popular with Armor crews, due to it's compactness. The Thompson would continue it's service life with not only The US Military (up to 1960), but other Countries Military's, with designs made up into the 1980s.