Thompson M1921 - Thompson M1921 is also known as “Tommy Gun.” It was designed in 1919, and it is named after the developer, General John Taliaferro Thompson. It is neither a pistol nor a complete machine gun. This gun is used by many police officials, soldiers, and security agencies because of its accuracy and lightweight. It weighs 4.69 kg and can fire 1000 rounds per minute, and it has an effective range of 100-150m.