I reloaded a batch of .308's & .30-06's for high power shooting last month and used a bunch of primers from boxes denoting a price of $7.99/1000, yet every round went "bang" when I pulled the trigger. I wish I hadn't used them all up, or better, I wish we could go back to the days we had those prices!
I never had a quality zip lock bag leak laying on a shelf in my reloading room. Even with a pin hole no moisture will go in from a dry room, if the bag is not accordianed.
Zip lock bags are moisture proof 100%. I use them for everything including storing silver (it doesn't tarnish), but you MUST put only dry things into them and dry air, and 'burp' the air out. ITC loves them.