Dispelling the Magazine Myth

[Titan6]

In my spare time I like to rid the world of bad information. Conventional wisdom holds that keeping your magazine full and not rotating them by unloading them is bad for the magazines and will result in the magazine taking a "set", whatever that is.

Recently I took a 15 month vacation to the ME and put my guns up that were not needed around the house for Mrs. Titan6 and the Junior Titans while I was gone. Before I did that I loaded up a variety of magazines for a number of different weapons from .22 pistols to ARs to big bore rifles. All told 20 magazines of different types and calibers for ten different semi-auto guns.

The magazines stayed loaded, most of them to full capacity for 15 months+. Today, during breaks in the rain I managed to shoot about most of them. You might might be thinking that that would be bad for the magazines and I would have jams and misfeeds and so forth. Happy to report there were no problems. Reloading the magazines did not produce different results. I do take good care of my weapons and don't normally have jams anyway. I also did not put much lube on my weapons before storage or any prior to shooting.

There are many good reasons to unload your magazines and check your loads especially for your carry piece. Dust, dirt, grime and "whatnot" gets inside the magazine and can cause jamming, misfeeds and so forth. But for long term storage there seems to be no issues provided the storage is in a clean environment.

 

[mcwjr13]

Welcome Home!

 

[Titan6]

Thanks, it is great to be home!

 

[CoRoMo]

This "argument" went on, some time ago, right here on THR. I've always felt that it is tactically wise to keep mags full, so I asked my brother, who's an engineer, about it, and he told me plainly that...

Springs weaken with use (cycles of compression and relief) rather than being compressed alone.

That was good enough for me.
The same should be true for those who store pistols with the slide locked. I always prefer to dry fire my guns before long storage to relieve springs, but I suppose that isn't necessary either.

Welcome back! And thank you!

 

[kwelz]

I really don't think it is "conventional Wisdom"

There is a lot of misinformation out there. People think it is common sense that a spring will form a "Set" however scientifically this doesn't happen.

 

[Geneseo1911]

Welcome home Titan; hopefully you had a nice, relaxing vacation...

 

[Finaltheorem47]

my dads kept his glocks mag full for the past 4 years w/out any problems.

 

[CGilbert74]

Very Timely

I have been googling every phrase I can think of on this topic, not much concrete info that I have found so far. I recently loaded up all of my AR and Mini-14 mags for gun safe storage and my friend told me I was nuts and was going to ruin my mags. I feel better now. Thanks!

 

[prickett]

Wolff springs (their website) has a blurb stating that leaving mags loaded for long periods (several decades) is NOT a problem.

 

[Grassman]

Forget the mags. A 15 month vacation!!!!!!! SWEET!!!!

 

[Illuminaughty]

I work at a gunshop. I keep every magazine I own fully loaded, much to the dismay of the guys I work with, even the gunsmith. I've never had a problem EXCEPT with Ruger 10/22 magazines and OLDER Hi-Point magazines. I like keeping my mags loaded because it's handy and because it tests the gun to see if the mag spring is crap. All of my AK mags, FAL mags, AR mags, CETME mags, Glock mags, S&W mags, Saiga-12 mags, and various other magazines have no problem being loaded all the time, so they stay that way.

I have a friend who loads/unloads all his mags constantly, because his Army Ranger friend told him it'd "set" the spring if he doesn't. I've told him my take on it and he says it's my opinion, but he thinks one day all my magazines are going to fail, and he keeps on doing what he's always doing.

Some people just never get it. There are some magazine springs that are just subpar, though. Some cheap gun manufacturers and some Rugers (10/22's and centerfire pistols) I've seen it happen to, too in the past.

 

[KelVarnson]

Yes, any spring WILL take a compression set due to being compressed for an extended period of time. That is an engineering fact. Cycling is not necessary in order for that to happen.

However, this "set" will reach a plateau that can easily be quantified, and a competent engineer will design their magazine (or other device) to function properly with this minimum value.

It ain't rocket surgery...

 

[CYANIDEGENOCIDE]

+1 on cycle not compression. Unless of course you exceed the elastic modulus for the spring

 

[Vonderek]

It depends on the temper of the spring. Quality springs will not set but crappy ones will. As an example, I have an 80's era Squires Bingham .22 mag that is useless. Didn't have many cycles of compression/decompression either. Only buy quality mags.

 

[Carl N. Brown]

I may have posted this answer to a similar question before.... but

(I am old, I can repeat a story).

Over a decade ago I bought an M1 carbine pouch with two loaded 15 rd magazines. The back story was that the pouch had come from an estate auction, the previous owner had brought it back as a WWII souvenir. The cartridges were headstamped '44' and were splotchy green and the magazines themselves were rusty in spots.

I unloaded the magazines, disassembled and cleaned them. They had evidently been left loaded from the end of WWII 1945 to about 1991, about 45 years. I still use them in vintage military rifle matches and those old springs, left loaded for nearly half a century, still have life to them. Properly tempered steel springs last a long time.

 

[KelVarnson]

I may have spoken too soon in my previous post. Below is some text that appears on many spring manufacturers' and other spring reference sites, discussing the relationship between full compression force and the minimum tensile strength of the material. I suspect that the majority of springs in practical applications fall into category 2, which is what prompted me to make my previous comments.

When the mags for my Sig P226 were new, it was all I could do to get the last round loaded. After sitting for a couple of days fully loaded, it was much easier, so they definitely took some compression set. But they still work fine.

1. Springs which can be compressed solid without permanent set, so that an extra operation for removing set is not needed. These springs are designed with torsional stress levels when compressed solid that do not exceed about 40 percent of the minimum tensile strength of the material.

2. Springs which can be compressed solid without further permanent set after set has been initially removed. These may be pre-set by the spring manufacturer as an added operation, or they may be pre-set later by the user prior to or during the assembly operation. These are springs designed with torsional stress levels when compressed solid that do not exceed 60 percent of the minimum tensile strength of the material.

3. Springs which cannot be compressed solid without some further permanent set taking place because set cannot be completely removed in advance. These springs involve torsional stress levels which exceed 60 percent of the minimum tensile strength of the material. The spring manufacturer will usually advise the user of the maximum allowable spring deflection without set whenever springs are specified in this category.

 

[saint]

Maybe I speak from ignorance here...

I heard that leaving a mag fully loaded is no problem for the springs (as seems to be the consensus here), but that the real problem is the stress on the feed lips. I would think that the same principle would apply for the feed lips (fatigue comes from cycling rather than from constant pressure)...but am I wrong? Is there any problem caused for the feed lips by leaving a mag fully loaded?

 

[SaxonPig]

Jeff Cooper wrote of leaving fully loaded 1911 mags at home for nearly 4 years during his WW II service and he was still using them in the 1970s.

I left some H&K 91 and FAL mags loaded for about 7 years and they also still work fine.

 

[expvideo]

My mags have been left full for 3 years. No issues.

 

[BADUNAME37]

Does the person who believes keeping a magazine loaded

ruins the spring take their car, truck, SUV or whatever and jack it up and put the frame on blocks for several months out of the year in order to "exercise" the springs?

After all, there is constant vehicle weight on the springs and look how long they last (if not used, but just sitting with the weight of the vehicle, perhaps 50 or 100 years or even longer).

Loaded, not loaded, cocked, not cocked, I believe whatever way you want to store your magazines and weapon is not going to hurt the springs one bit.

If you happen to live 500 years, then MAYBE there might be an issue -- maybe, but then maybe not!

 

[DoubleTapDrew]

Yes, any spring WILL take a compression set due to being compressed for an extended period of time. That is an engineering fact. Cycling is not necessary in order for that to happen.

However, this "set" will reach a plateau that can easily be quantified, and a competent engineer will design their magazine (or other device) to function properly with this minimum value.

I think some do take a little bit of a set at first, and that can be a good thing. Glock magazines for example, are an absolute pain to load to capacity when new, but after a week or two of being loaded they get easier, yet keep good, consistent tension from then on.

 

[Titan6]

I have noticed something similar with Glock magazines as well. I have always assumed this had to do with the polymer smoothing out and not to do with the spring, although I have never really examined that issue fully.

 

[ServiceSoon]

I find it hard to believe that a static load (compressed spring) won't wear it out-decrease the spring pressure-cause fatigue. Obviously a cyclical load will cause that fatigue to occur sooner.