Magzine spring shelf life

[AR15_Fanatic]

If one stores their ammunition for their weapons loaded into the magazines, how long can the magazines remain loaded before the springs start to deform and lose their compression?

[surbat6]

There is no good single answer to that question, AR15. Generally, magazines made after mid-20th century have springs that won't lose too much power if left loaded for long periods, but most gun folks I know will keep a few mags loaded for, say a week or two, then rotate with unloaded ones.
Personally, I keep a revolver or two loaded and wait until there's need to fill mags for semi-auto pistols or rifles.
Quite a few shooters go so far as to release pressure on hammer springs when guns go back on the rack. Others don't, and have no problem.
Sounds like a good test. I'll load up a mag or two for the FAL and leave them that way. Next year, I'll try to remember to post results.

[SCCogswell]

Back when 90-odd countries were buying FALs, they would typically order a few jillion magazines with the rifles. One of the options was to order the mags already loaded, so FN certainly wasn't worried about their mag springs. There is a school of thought that magazine springs can be kept loaded essentially indefinitely without loss of tension. Many have noted finding mags (mostly pistol) loaded in the 1940s that still fed reliably. Some folks believe that it is the compression/release cycle that wears 'em out, ie. the typical practice of "rotating" loaded magazines is actually increasing wear. I've got M-14 mags that I know were loaded at least a decade before I unloaded them and the springs were fine. I've stopped worrying about it.

[Seeker]

I read an article in a magazine once that addressed the issue of storing loaded handgun mags for self defense, it concluded/suggested that magazines can be kept loaded for about year before they should be unloaded and rotated to let the springs rest. Now if I was to make an assumption without making a 'donkey' of myself and you as well I'd say that would work with pretty much any magazine, but I'd also consider the quality and craftsmanship of each mag individually.

[swill269]

:o
the binding and releasing of the spring fatigues the metal more than keeping it loaded as SCCogswell stated. ;)
:cool:

[Metaldoc]

SCCogswell is correct (as Swill observed). When metal fails it is quite often (not always) due to 'metal fatigue'. A simple example is bending a piece of wire back and forth until it breaks. Springs are tempered steel. This is what gives them their stiffness and inclination to return to their normal unloaded state.

There are a lot of conditions that must come together to make a good reliable spring. The metalurgy must be right in the first place, the thickness, the correct temper, the amount of deflection. If you bend the spring too far, it will finally yield and not return to the original position. It has become weakened at that point.

In a properly designed magazine, with a properly manufactured spring, that yield point is not reached so the spring does not become weakened or lose it's 'memory'.

Well made quality mags left loaded are not likely to fail because of loss of spring tension. But other factors can come into play. Dirt and corrosion, lubricants becoming sticky, etc. Use quality mags & ammo and keep em clean & dry.

Metaldoc :usa: