Thompson Sub-Machine Gun
Colonel John T. Thompson
John T. Thompson
As an ordnance officer in World War I, US Colonel John T. Thompson dreamed of a new weapon that could be used to infiltrate trenches and kill the occupants. After the war he set out to design a light-weight, fully portable machine-gun that attacking troops could fire on the move. Thompson realised that existing machine-guns had too many heavy components. They would all have to go.
In his new design, the only heavy, moving part was the bolt. In each cycle the bolt simply flicked out the spent cartridge while a spring-loaded magazine loaded a new one. This was the first sub machine gun, less than a quarter of the weight of existing weapons like the Maxim gun.
Thompson called it the "Trench Broom", a weapon to sweep away the static warfare of the past. Everyone else called it the "Tommy Gun" The distinctive circular magazine carrying up to a hundred rounds could be emptied in less than seven seconds. But, the war was over and the US army didn't need such a new-fangled weapon. Someone else did! - Gangsters.
1920s mobsters like Al Capone were quick to spot the potential of a weapon that could wipe out their enemies fast.
The Tommy Gun
The Tommy Gun became an icon of death and destruction. The stuff of blood-thirsty newspaper stories and Hollywood movies. It was the must-have accessory for any gangster on the make and the police were soon forced to get Tommy Guns of their own.
But, the first-ever mob hit with a Tommy Gun didn't quite go to plan. spike O'Donnell ran a major bootlegging operation on the south side of Chicago. On September 25th, 1925 mob rival Frank McErlane set out to kill him, armed with a Tommy Gun and an unknown quantity of ammunition. What happened next gave them both the shock of their lives. McErlane missed with every single shot. What had gone wrong?
The early Tommy Guns were not very accurate as the barrel had a tendency to rise with the force of the muzzle blast. Later models were fitted with a, so-called, Cutts compensator which appeared in 1926. This works by diverting some of the blast upwards forcing the muzzle down. The Tommy Gun became a highly effective close-range killer.
Cutts Compensator in Use
To give the weapon greater precision, Thompson gave the gun a semi-automatic option where it fires and reloads just once for each squeeze of the trigger.
CREDITS: All of the above information was taken from the UK's Channel Five "Inventions of War" documentary series.