This open-bolt submachine gun is one of Israel's most significant contributions to modern warfare. It was designed by noted gun designer Uziel Gal in 1948 and several of its variants are still in production. This gun can fire 600 rounds per minute and has a muzzle velocity of 400m/s, which you can take to mean as "a LOT". Until recently, this gun was also used by the Special Protection Group, which is responsible for guarding some of India's most powerful people.
Tommy Gun aka Thompson
Source : http://guylife.com