This is a question that comes up a lot for preppers and gun enthusiasts. The answer truly is “Depends.” The key is the quality of the spring within the magazine. A cheap quality spring will “set” itself and not expand like it should. Without the pressure pushing the bullets upward this can cause bullet misfeeds. This typically happens after years of storing a loaded magazine. Higher quality springs will work just fine and many people attest to pulling out magazines that have been stored for up to 5 years and having no problem. However good practice is to pull the spring out of the magazine and let it stretch every once and a while. This will expand the spring and help unset it. You should find it will regain some of its expansion properties afterwards. However don’t manually pull it this could damage it.
Frequent usage is the key thing that will weaken springs overtime. As the constant expand and contract work to release some of the stored up energy. As well there is an elasticity range of motion for the spring. Damage can occur if the spring is compressed or expanded beyond this point. So ultimately higher quality magazines you should be ok. Since a magazine is a key factor in a potential firearm malfunction I would recommend spending the extra money on good quality magazines. For instance while cheap $5 1911 magazines are available getting a $30 Wilson Combat is a better option when you think of it as a life saving device.
Magazine Rotation and unused stockpile
Unfortunately you really won’t know if a magazine’s spring is made from a quality metal until after you have stored ammo inside for quite a while. To prevent the potential of weakening the springs many preppers keep only half of their magazines full and then every 6-12 months rotate which are full and which are not. Other preppers like to keep separate magazines stashed for use in SHTF. That way they know those springs will still be good.
Either way if you are concerned about loaded magazines there are ways to hedge your bet on this debate. Personally I’m the “All-Mags-Full” kinda guy. However once my prepping turns to homesteading you will find me stockpiling some unused magazines for barter or use in SHTF. My opinion on this discussion is when you need them you won’t have time to load them. So have them ready to go at a moment’s notice. Something that goes bump in the night certainly won’t require a tac vest full of loaded mags but if I need to bug out you know I would rather they be loaded.
Final Note on Springs
You know one thing I think might be worth investigating in a future article would be creative uses for springs. These are like batteries of kinetic energy. In the same way you store electrical energy into lead acid batteries, you can store motion into a battery through a spring. Typically if you energy or motion you can make the other. So springs may be worth some attention in doomsday engineering. If you have any ideas of great uses for springs in SHTF leave a comment below.