So it seems to be pretty common to have multiple loaded mags in the home. But someone mentioned changing them out to keep the spring fresh. So how long is TOO long to keep a mag loaded without firing or unloading it?
I don't worry too much about rotating mags in my carry gun since I'm usually shooting it every month at least. I'll unload 'em at the range and load 'em with my practice loads, then reload with the carry ammo when I'm through. In ten years, they haven't failed, yet.
If by chance I haven't shot the gun for a while, I'll unload it and let it sit for a few days while I carry my revolver. I just don't like them sitting up too long, have had mags "take a set" when loaded for a long time in the past, admittedly on a rim fire gun. My Mec Gar mags seem to be pretty high quality, though, and I don't know if they'd have a problem leaving them loaded for a year or more, just don't take the chance. Also, in my experience, double stack mags are more prone to this than single stack mags.
If you're willing to trust the gun leaving the magazines loaded for extended periods, fine, but I'm not. I know that I've left my carry loaded (9mm double stack) for a couple of months and it's fed find, makes me happy with my routine. Better to be safe than sorry. I don't knew that there is any rule to this deal and I'm sure there are guns you could leave loaded forever and never have a problem, just my routine makes me feel warm and fuzzy. Being basically a revolver shooter in the past, I still distrust the autochuckers somewhat. I'm getting less and less that way, though. My guns are all good performers. I've owned ones in the past that weren't and got rid of 'em.