In 1921, the Colt Patent Firearms Company made 15,000 Thompson submachine guns for Auto-Ordinance at a cost of $38.25 each. These were called the “Model 1921A”. This model weighed and had an effective range (distance it was accurate) of . General Thompson tried to sell his gun to European countries with little success. He tried selling it in the US but sales were slow. In 1926 he got orders from the United States Postal Service and the United States Marine Corps. The Marines used the guns during the Banana Wars. It worked well to counter ambushes by Nicaraguan guerrillas. The Irish Republican Army used them in 1921 during the last part of the Irish War of Independence. They were not impressed by the fact they could only kill about 32 percent of those they fired at. Others who bought his submachine gun included Law enforcement agencies and ranchers. Organized crime quickly found uses for the gun. Later, the United States Navy ordered 1,500.