Are you sure you are crushing your primers and not simply seating them correctly?

You want the primer to seat slightly below flush with the case, if using a hand priming tool, you should feel the andvil crush slightly as it seats- you want the anvil to crush a little so that when the firing pin hits the primer, it dosn't have to waste any of its energy prshing the primer forward to seat the anvil before igniting the primer.

Does your hand primer seating device have a pin in it for pushing the primer in? I use a RCBS priming tool, and there is a rounded end and a flat end to the primer seater- You mush use the flat end- the ends look fairly similar if you don't pay attention, not sure if lee's device is similar.

I would store your primers in a dryer spot- maybe one of those surplus ammo cans with a good tight seal on it along with some dessicant pouches.