Joe at Prepping to Survive had a followup comment to the question posed to Max regarding mags that I thought warranted a post:
Would like some advice on how long magazines for the AR15 and M1A should
remain loaded (less one round left out while stored away.).
Anonymous - That's a great
question and one that's frequently asked. There's seems to be a lot of
misinformation out there about it.
I've done a fair amount of
research and experimenting of late and have found that there is a
difference in spring fatigue and spring creep.
Spring fatigue (the
continued compression and expansion of a spring) is a real concern for
magazines. The more you shoot, reload, and shoot, the quicker your
magazine springs will begin to fatigue.
However, spring creep
(simply keeping the spring compressed for a long period of time as in a
storage situation) is not a concern.
So, the short answer is,
keep them loaded. If you're interested in a long discussion, I've
written about it here:
(Archer Adds: Thanks Joe for the followup on an eternally relevant topic)