I don't tumble loaded rounds and I really don't know how much time it takes to tumble ammunition and have problems.
When I called the Army Ammunition Safety Group to talk about a bulletin of theirs, I got to talk to a couple of the good guys there. These were logisticians who were ex GI’s. I was informed that if ammunition stored on tracked vehicles has to be “cycled” because of pressure and function problems encountered if the ammunition is kept on the vehicle too long. Tracked vehicles have high amplitude vibrations, if you have never ridden in one, they are uncomfortable and noisy.
I believe the gunpowder in the ammunition in these vehicles is being mechanically broken down.
If I'm not shooting, I'm reloading.