"Uncontrolled de-compression" is never a good idea.
But I doubt you hurt the drum.
Remember in firing from the drum, each recoil sequence "shakes" the drum pretty well; the shake you gave it to move the cartridge column is similar.
It will probably work just fine when you fire it.
But please, only use it in a luger that works 100% with 8 round magazines; any pistol problem with feeding, extraction, or ejection is only magnified when using a drum- original or GT improved.
