Tommy Gun -600rpm shown with 100 Round Drum Magazine
I think “Tommy Guns” were usually outfitted with 20 to 30 round magazines. Perhaps those 30 rounds could be fired in 5 seconds? (Or whatever). But 600 rounds in 60 seconds?
Sort of like saying a car that can reach 60 mph in 5 seconds will get to 720 mph in a minute.
600 rpms for a Thompson is actually pretty slow. Many models could do more like 900-1000, with a couple even running 1200 cycles a minute. As far as I’m aware, the only Thompsons that could fire as slowly as 600 rounds a minute were built on navy spec, which included a rate reducer to reduce it’s rate of fire.
If you’ve ever handled machineguns, 600 rpm is quite slow.
Your post is exactly correct, but there was a "C type" drum that held 100 rounds.
Tommy Gun -600rpm shown with 100 Round Drum Magazine
I’ve fired a Tommy Gun, even with the 50 round drum magazine, at 600 rounds per minute, the Thompson would be empty of rounds within 5 seconds, requiring a magazine replacement. There is no way anyone can achieve 600 rounds per minute. In actual fact, the cyclic rate of fire of a Thompson is about, 800 rounds per minute for model 1921, 750 rounds per minute for the 1927, and 1100 rounds per minute for the 1919 model. For the later, it could burn through 50 rounds in 2.4 seconds. No one could control the gun accurately in full auto due to recoil. It tended to climb up and to the left. What people see on TV and in the Movies are modified guns firing either natural gas or blanks, depending on whether or not they wanted to depict it ejecting spent rounds. Shooting it was and is an expensive thing to do unless the shooter is not paying for the ammunition of the wear and tear on the barrel.