[Fiddlstix]

I heard the fifty round drum magazine had problems with jamming. Is that true?

I'm not sure about that. I've never owned a Thompson myself and only shot a couple of them. The ones I shot had the 30 round "sticks".
Bender2 would probably know the answer to your question.

[Bender2]

I heard the fifty round drum magazine had problems with jamming. Is that true? I'm not sure about that. I've never owned a Thompson myself and only shot a couple of them. The ones I shot had the 30 round "sticks".

The 50-rd drums (And even 100-rd ones) could jam if not loaded or maintained properly. They were both 20 and 30 round 'stick' magazines but you never loaded 20 nor 30 rounds. You loaded 18 & 28 as this would keep the springs in better condition and keep the 'sticks' from jamming.

Here is a Model 1921 with 100 round drum:


and a 1928 with 50 round drum:



Hey, you pudknockers, don't ever... sell the 50 round drum short!