tumbling live ammo in a vibrator tumbler?
I never use a lid. I like to see the brass vibrating. I fill the vibrator half full of crushed walnut shells. I drop the brass and live ammo in while vibrating. I don't over do it where the cases touch much. vibrate a few hours while checking to see how there doing. depending how clean I want them I'll dump the walnut shells put in cleaner walnut shell. I have 3 tubs walnut shells dirty, fairly clean, and clean. I have been reloading about 30 years and have not heard or experanced any accident tumbling live ammo. Use common since. That's just my way, works for me.