I have 3 boxes of Federal .40 hollow point rounds I keep in my home for self defense. I anticipate this ammo to be stored for a long time (hopefully) in a safe. First of all, how long can ammunition be stored and still be considered worthy? Secondly, is it acceptable to keep two Glock 22 15 round clips loaded indefinitely? Will it wear the spring? Will the pressure of the clip spring be detrimental to the bullets over time? I am talking years here.