Okay, how about I prove there's nothing to worry about?! Since I'm "into" disproving loaded round tumbling being dangerous, how about I take 50 rounds of the same 40 S&W I just tumbled for 48 hours, go outside, bury 25 in a snowbank? 50 round midway/FA box, open, bullet down, case base up. Another 25 from the same batch saved inside where I normally store the ammo.
How's 6 months sound? That would be June 23rd. Exposed to snow now, melting then rain, sun and everything else central Wisconsin can throw at us. It'll take a while, but should prove whether that will cause problems. I'm betting it won't.
What do ya think? Should I?