Possible Clues:

• Weapon favoured by Prohibition-era gangsters
• Mount Cook overlooks exercise centre set up by one fired for fighting during second World War
• 1920s weapon nickname (2 words)
• Weapon in old gangster films
• Prohibition-era weapon
• Cat got my tongues at the centre twisted by old fiery type from the war!
• Cat got my piece in second World War museum
• Firearm also called a "Chicago typewriter"
• Light American weapon of WWII
• Thomas was made to do the shooting