think about all that 50-80 year milsurp ammo that gets shot every day..
FWIW.. I keep all my powder cans in sealed contaners or ziplock bags ( IE.. the entire powder coantiner in a ziplock, in the case of 1# cans.. or the larger in sealed plastic tubs, container intact.
I keep all my dies in ziplocks.. as well as primers. I'm starting a campaign to ziplock ALL my boxed and bulk ammo.
long term thinking here..
my stuff stays in climate control.. but it never hurts...