Will keeping a fully loaded mag REALLY wear out the spring?

[Cosmodragoon]

I've seen a lot of folks, here and elsewhere, caution against keeping fully loaded magazines because it can wear out the spring.

I know from physics that springs tend to lose elasticity under prolonged compression. The rate of loss depends on several factors from spring construction to temperature. The question is how long it takes to lose crucial elasticity. (That is when the loss goes beyond operating tolerances and starts causing failures.)

I'm no expert but I've had magazines loaded for years without issue. That goes for those in straight storage and those that simply get refilled every time they are used. So for those with more experience, how many failures have you seen from this? What king of failures do you see? Is it a marginal issue where things just seem to work less well overall? Is this even a real concern?

[JohnKSa]

Short answer:

It can be an issue, but it's much less of an issue than in times past. And it depends heavily on the magazine and type of magazine. Single column mags virtually never seem to weaken from being left loaded and it's not common with double-column mags anymore.

Long answers:

http://thefiringline.com/forums/showthread.php?t=527697
http://thefiringline.com/forums/showthread.php?t=416174
http://thefiringline.com/forums/showthread.php?t=393838
http://thefiringline.com/forums/showthread.php?t=433756
http://thefiringline.com/forums/showthread.php?t=524727
http://thefiringline.com/forums/showthread.php?t=494514
http://thefiringline.com/forums/showthread.php?t=454204
http://thefiringline.com/forums/showthread.php?t=442487

The solution is simple and it's not one that requires anything that we shouldn't already be doing.

Check your magazines periodically to see if the springs are weakening or if the magazines no longer work reliably. Everybody should be checking their self-defense equipment regularly anyway. If one of the checks indicates that there is a problem, replace the springs with high quality replacements. If the problem repeats, replace the springs again but also underload your mags by a round or two in the future. Or leave them fully loaded and determine a reasonable cycle for periodically replacing the springs.

[stormyone]

Shorter answer: No.

[Cheapshooter]

You just asked one of those trigger questions like mentioning Taurus, High Point, or the defensive capability of 380 ACP!

[JohnKSa]

Short is nice. Accurate is much better.

http://www.ar15.com/archive/topic.ht...&f=13&t=127595

Two persons on the linked thread had their magazine springs weaken to the point of inducing malfunctions from leaving them loaded.

***************************

"My G27 mag springs crapped out after having been left loaded for about seven years. Lots of failure to chamber, with the rounds nose-diving into the feed ramp.

They had been used very, very little in the years preceding that point.

Replacement with new OEM springs solved the problem immediately."

***************************

"I do have one Glock 20 mag with an Arredondo extension on it, with a +10% spring. It should hold 20 rounds, but I had it loaded for about 2 years with 19 rounds and the spring took quite a set. When I went to empty the mag by hand, the spring didn't have enough power to push the rounds up."

What's funny is that you see poster after poster on the same thread repeating the mantra that this never happens as if it will somehow change the facts.

I shot airguns before I got into firearms and was amazed to find that what was common knowledge in the world of spring-piston airguns; verifiable truth established by repeatable experiments and confirmed by manufacturer recommendations; was nearly totally unknown in the firearm world.

One of the primary reasons for the advent of gas-pistons was to avoid the inevitable weakening of the metal springs in spring-piston airguns encountered when the gun was left cocked (spring left compressed) for long periods of time.

I've asked before why springs in airguns are somehow different from the springs in firearms but no one ever seems to have a good answer. Not that it changes anyone's mind. People seem to have very firm beliefs on this topic and are remarkably unwilling to allow their beliefs to be altered by facts.

[armsmaster270]

I have had no problems with Sig mags kept fully loaded for 10 + years.

[odugrad]

They should be fine. The main thing that will wear out springs is loading them, unloading them, loading them, unloading them, loading them, unloading them repeatedly. If you can, have some mags for the range and some that you keep for self defense purposes.

[Cheapshooter]

I didn't bother sorting through the many links posted, but I know there have been many post by metallurgists stating that flexing, repeated compressing and decompressing springs is what weakens springs.
So like in the threads I mentioned, believe which ever side you choose.

[Walt Sherrill]

Originally Posted by odugrad

They should be fine. The main thing that will wear out springs is loading them, unloading them, loading them, unloading them, loading them, unloading them repeatedly...

Not necessarily true -- and people who know metallurgy, who know springs, or who understand the practical aspects of physics tell us a different story.

It has more to do with HOW the springs are used than HOW FREQUENTLY they are used. As one observer noted, if compression alone was a controlling factor in spring life, we would have to replace recoil springs far more frequently than we replace mag springs -- but we typically don't...

While cycling springs can wear them out, leaving them fully (or nearly fully) compressed can wear them out more quickly. Not all mag springs are fully (or nearly fully) compressed when the mag is loaded. (It's enough of a concern that Wolff Springs, in the FAQ area on their website, recommends downloading some mags a round or two for long-term "loaded" storage.)

In defense of those who say it doesn't matter -- based on their experience -- most mag springs will outlive the shooter, but some won't. The term "elastic limits" comes up in this type of discussion a lot. While most shooters won't have a problems with their mag springs, if YOU have hi-cap mags or sub-compact mags that are left fully loaded, you MIGHT.

At least one metallurgist (an engineer trained in the art and science of metal making) who participates here from time to time, familiar with spring design and use, has provided input to earlier discussions, as has another engineer who has made it a hobby to investigate spring life issues. JohnKSA, in addition to his other contributions on this topic, provided one link on airgun spring life (about the effect of leaving springs fully compressed) that was an eye-opener! JohnKSa is also an engineer, if I remember correctly.

Check John's "Longer Answer" links, above for details with technical citations and evidence. We've had other lengthy discussions, here, on this topic, and John's links are some of the shorter ones. The final link in that list includes input from danez71, who has spent a good bit of his time (as a hobby?) pulling together technical links about spring life, but John's "longer answer" replies are pretty succinct in their own right.

[Skadoosh]

Four factory Glock mags fully loaded since 1994: zero problems. Four Mec-Gar 8-rnd mags fully loaded since 1997: zero problems.

I know from physics that springs tend to lose elasticity under prolonged compression.

Which law of physics are you referring too?

[Cheapshooter]

Short is nice. Accurate is much better.

Of course other than the two "accurate" reports there are these other 5 other "accurate, first hand" reports from that same thread!
Wouldn't accuracy be including all first hand experiences, not just the two that support one opinion?

My duty/defense ammo mags stay loaded and don't get beat up like my range mags. I shoot out the duty/defense ammo out of them when I replace ammo and to make sure the mags are still working. I have some mags that have been loaded since 2003 no issues yet.

They'll be fine for a long, long time.

I carry a G21 as my duty gun at the PD. I've had it since '92 or '93. When the AWB became law, I bought 3 LEO mags for duty use, since pre-ban G21 mags soon shot up to around $100 each and I didn't want to worry about replacing my pre-ban mags. I've been carrying these same 3 mags since '94 with no problems at all. They always stay loaded and are shot probably every couple of months when I practice. No problems, they still work just as well as when they were new. Also, I have a bunch of G21 mags I bought before the AWB. All have been loaded since purchase and all still work 100%.

I have shot 1911 mags that were loaded for decades... and tossed in a desk drawer before we got air conditioning.
Btw the ammo was still fine too without being sealed in a vacuumed Mylar bag with the moisture bags and put in a ammo can and stacked in a dehumidified, climate controlled room and rotated so the sediment wouldn't settle...

I had a Glock 17 that stayed loaded for 14 years, except when emptied at the range. Never had a problem with it

given that I am old and have some mags loaded since I was young, I will chime in on this, too. I teach NRA pistol classes and Texas CHL classes and have seen a lot of students with mags that they say have been loaded a long time. Their gun will malfunction, and we get into the "this has been loaded a long time and I never shoot it conversation. then some expert pops us and says you have to rotate your mags every week/month/year/whatever. Without skipping a beat, I usually disassemble the mag, clean out the buggers, coffee/cream/sugar residue, and the mag works just fine. As others have said, load them, forget them etc. just keep them out of the soup.

(Emphasis added because that may very well be the cause of the problems in the two examples of supposed springs weakening}

[40-82]

I have a pair of Wilson 8-shot 1911 45ACP magazines I bought in about 1982, except for emptying them when shooting or maybe changing loads, they've been loaded since. In all of my years of shooting I've never had a failure to feed that I could attribute to a weakening spring in a modern high quality 1911 magazine. That said, if it is made by man it can fail. Check them regularly.

[Tactical Jackalope]

I can say stories of what guns where loaded for X amounts of years, etc etc.

Just short and sweet, no. What wears down a mag spring is constant use. Compressed/Depressed/Compressed/Depressed.

[Elliottsdad]

Another vote for "no."

[Walt Sherrill]

Originally Posted by Constantine

Just short and sweet, no. What wears down a mag spring is constant use. Compressed/Depressed/Compressed/Depressed.

Is that why tappet springs on cars fail so frequently? They arguable get millions of cycles in a couple of years.

[Kevin_d77]

"or who understand the practical aspects of physics tell us a different story."

As a structural engineer who understands physics quite well, I have seen no evidence or proof to believe that constant compression will wear out a properly designed spring. Like most things in life, your trust lies in believing that people are competent at their jobs. If you worried that an engineer or designer wasn't capable to perform their job, I would think most people would feel pretty uncomfortable flying or driving cars that someone else designed. But that's just me in my classic physics trained, logical brain.


*edit- springs will wear out under constant compression IF they are heated to extreme temperatures so if you leave your springs compressed on the sun then they will degrade simply by constant compression. That being said, if a spring is not designed properly for its intended load (which should not be a very mathematically intense design), then it could fail. But if you're worried about incompetent design, I would think the simple act of firing a gun would be more worrisome than magazine spring design.

[Tactical Jackalope]

Is that why tappet springs on cars fail so frequently? They arguable get millions of cycles in a couple of years.

Tappets? Old technology...lol then again way bigger/thicker springs meant to take 7-8,000 rpms.

[Walt Sherrill]

...As a structural engineer who understands physics quite well, I have seen no evidence or proof to believe that constant compression will wear out a properly designed spring.

And what is a properly designed spring? Is it one that lasts a long time without replacement, or one that lets a magazine hold an extra round or two in the space originally intended to hold fewer rounds? I've been told there aren't any free lunches... and the trade-off between the first example and the second has to have real-world costs.

Nobody is saying that all mag springs will fail from staying compressed. In fact, many mag springs aren't highly stress when compressed. That is certainly true of 7-round 1911 single-stack mags. It seems less true with some sub-compact mags, like the Kahr P9, with which I've had some experience, and with some hi-cap mags. That said, I've never had a 10-round mag spring fail in a full-size 9mm handgun.

As I have noted before, the same mag spring is used in the CZ 10-round and CZ 17-round mag. One full compression cycle with the 17 round mag causes that spring to lift 70% more material than the 10-round mag, and the 17-round mag spring clearly must be compressed far more fully than the 10-round spring. Would a reasonable person really expect those two springs to have the same service life in normal usage, if we count only the cycles (from full to empty)? They are, afterall, the same springs and same number of cycles, but arguably a much different work load. How about if the the two mags are stored fully loaded? Is the stress on the springs the same? I'd argue that when stored, those springs are still working (in one sense, at least), pressing the rounds in the tube up against the mag's feedlips.

Springs will degrade over time. How quickly they degrade will depend on WHEN they are used (i.e., the frequency of use) and HOW THEY ARE USED -- but cycling them alone, as some claim, isn't the only factor affecting spring life. It will also depend on how close to the spring's elastic limits their regular use pushes them; science tells us that the closer to that elastic limit the springs are pushed, the greater the degradation they'll experience. As others have noted, that is a fact that is well supported by a lot of data.

danez71 made the following observation in one of the links cited earlier, with regard to the physics issue:

Originally Posted by danez71

Creep/sag/viscoelastic deformation.... call it what want. The fact is:

"All materials exhibit some viscoelastic response. In common metals such as steel or aluminum, as well as in quartz, at room temperature and at small strain, the behavior does not deviate much from linear elasticity. Synthetic polymers, wood, and human tissue as well as metals at high temperature display significant viscoelastic effects. In some applications, even a small viscoelastic response can be significant. To be complete, an analysis or design involving such materials must incorporate their viscoelastic behavior. Knowledge of the viscoelastic response of a material is based on measurement"

Until someone posts some actual verifiable evidence to the contrary.... there isnt any logical reason to doubt science.

danez71 cites other technical sources showing how springs can degrade over time, with use and when left compressed. Wolff Springs (in the FAQ area of their site) offers guidance on this matter, and they mention "elastic limits." JohnKSa also cites a test of airgun springs that shows similar degradation.

Perhaps you can offer us some evidence to support your contrary position?

.

[Kevin_d77]

"All materials exhibit some viscoelastic response. In common metals such as steel or aluminum, as well as in quartz, at room temperature and at small strain, the behavior does not deviate much from linear elasticity. Synthetic polymers, wood, and human tissue as well as metals at high temperature display significant viscoelastic effects. In some applications, even a small viscoelastic response can be significant. To be complete, an analysis or design involving such materials must incorporate their viscoelastic behavior. Knowledge of the viscoelastic response of a material is based on measurement"

Notice the statement of "high temperature". I don't have time to prove what is already know in physics, but reading thru the links and articles posted here has not provided me with enough evidence to negate my believe that fatigue caused by cycling is the main cause of spring degradation. So until something that is brought up that changes my understanding of simple physics, I will not change my mind.

Your arguements might seem more valid if you actually had a background in physics or engineering and I certainly wouldn't chime in on these discussions if you left out the petty remarks and underhanded insults. Just because I have had a bank account for 30 years doesn't make me an expert or more knowledgeable in banking (your field) so just because you have owned guns doesn't make you an expert in physics

[Kevin_d77]

From "Design and Analysis of Machine Elements" by Douglas Wright, Section on springs "if a compression spring is designed with the yield limit above the solidity limit and manufactured correctly, the ONLY way it can fail is through fatigue"

Unfortunately my basic physics, structural dynamics and harmonics and material science engineering books are all at home so I can't quote them but here is one quick reference I found online.

[henry1960]

No...I take two magazines to the shooting range which I only use for that reason..My other three magazines I keep full and used for defense only which they have been for thirteen years...Like they say what wears out a spring is the use of you using it, not keeping it full....

[Spats McGee]

Dagnibbit, I'm a lawyer, not an engineer!

Here's my question. I don't leave mags loaded for years on end. I go out and shoot, often using the same magazines that I carry. After all, I want to know if the magazines are working properly, too, right? Whether it's leaving them loaded, or compression/decompression that wears them out, this doesn't sound like a problem that's going to crop up all at once "Surprise!," now is it? Wouldn't there be some indication over the course of several range trips that something isn't right? FTF, maybe?

[Walt Sherrill]

Originally Posted by Kevin_D77

"All materials exhibit some viscoelastic response. In common metals such as steel or aluminum, as well as in quartz, at room temperature and at small strain, the behavior does not deviate much from linear elasticity. Synthetic polymers, wood, and human tissue as well as metals at high temperature display significant viscoelastic effects. In some applications, even a small viscoelastic response can be significant. To be complete, an analysis or design involving such materials must incorporate their viscoelastic behavior. Knowledge of the viscoelastic response of a material is based on measurement"

Interesting that you ignore the first sentence, which says "all materials," while focusing on the second -- which emphasizes high temperatures and resulting SIGNIFICANT viscoelastic effects. It also says that in some applications, even a small viscoelastic response can be significant, and that doesn't seem limited to the effects of high temperature.

Please note: nobody has been been talking about extremes or the effects of high temperature-induced viscoelastic effects. We're talking about the more mundane effects of spring behavior when springs are pushed to or beyond their elastic limits. High temperature is not required.

You also seem intent upon making this discussion personal, attacking my lack of engineering credentials rather addressing the points I make. That may seem effective to you, but I'd rather see you offer evidence that the things I (and others) have written are wrong. You haven't really done that. If what I've written here is wrong, I'd like to know it -- as I want to learn, too. Instead, you seem intent upon arguing from authority in hopes that your professional credentials rather than presentations of evidence or data will make your case for you.

Can you tell us how the training and education of a Structural Engineer differs from that of an Metallurgist? As I understand it, a metallurgist is someone concerned with the physical and chemical behavior of metals and alloys.

The metallurgist who participated in the prior discussion on this topic offered responses similar to mine, and confirmed the points made by danez7. As have others, here, in this discussion. For some reason, you didn't take the metallurgist or danez71 to task for their lack of understanding even though their arguments were essentially the same as mine (albeit better presented). Both of them disagreed with you.

Make your case and offer your evidence or facts.


.

[TunnelRat]

Didn't we just have one of these friends? Why do we keep needing to rehash this?

[JohnKSa]

Of course other than the two "accurate" reports there are these other 5 other "accurate, first hand" reports from that same thread!
Wouldn't accuracy be including all first hand experiences, not just the two that support one opinion?

The two reports indicate that it CAN happen, the others indicate that it doesn't happen all the time.

The problem is that people assume that because it hasn't happened to them, or because it doesn't happen all the time that it CAN'T happen.

I can say stories of what guns where loaded for X amounts of years, etc etc.

Which proves ONLY that it doesn't happen every time. It does absolutely nothing to prove that it CAN'T happen.

Clearly it can, and it does. It doesn't take too long to find cases where it has happened.

It just doesn't happen all that frequently and it almost never happens with decent quality single-column mags.

As a structural engineer who understands physics quite well, I have seen no evidence or proof to believe that constant compression will wear out a properly designed spring.

And you probably never will if you get to pick what is meant by "properly designed".

However, it certainly is true that constant compression can wear out high quality springs in real-world products and here is the proof.

http://www.network54.com/Forum/79537...re%27s+a+test-

Note that all the springs tested lost power from being left compressed and they lost more power the longer they were compressed.

Tom Gaylord, noted airgun expert performed a similar test with similar results that he published in his excellent book on the Beeman R1.

Spring-piston airgunsmiths and makers have to know about springs to make living. They'll all tell you to minimize the time the gun is left cocked to prevent the spring from weakening while at the same time pointing out that shooting (compressing and releasing the spring) is much less damaging to the power & life of the spring.

Getting back to firearms, here's a case where an armorer responsible for a large number of pistols over a couple of decades tells what his experience has been.

http://glocktalk.com/forums/showpost...&postcount=162

From "Design and Analysis of Machine Elements" by Douglas Wright, Section on springs "if a compression spring is designed with the yield limit above the solidity limit and manufactured correctly, the ONLY way it can fail is through fatigue"

The assumption is that all designers who use springs insure that all the stated limitations are met and all manufacturers manufacture springs correctly.

The fact is that sometimes a designer may find it ADVANTAGEOUS to design a magazine spring (or a spring-piston airgun spring) so that it doesn't meet those requirements. And, of course, there's no guarantee that all the springs we buy are manufactured properly.

You (and Douglas Wright) are correct that it's possible to manufacture springs that won't fail/weaken from being left compressed. HOWEVER, in some cases the designer chooses not to design the springs as a normal wear item to be replaced at regular intervals. Why would they do that?

Because it helps keep weight down, it pushes mag capacity up a little and it makes loading the magazine easier (a spring made of smaller diameter spring stock is lighter, means more room for cartridges and is easier to compress). In spring piston airguns, it maximizes power while minimizing weight, size and cocking effort. In both cases, the spring lasts a very long time if used properly and is typically not expensive (or at least in the case of magazines) difficult to replace.

Even if one refuses to accept the idea that their definition of "properly designed" isn't universal, it's still clear that not all springs are manufactured properly. For that reason, even if for no other, it's unwise to spread the idea that springs can't weaken from being left compressed. Clearly anything manufactured can be improperly manufactured and when that happens, all bets are off.

Does this mean that all magazine springs will weaken if the magazine is left loaded? No--but it absolutely does mean that some magazine springs CAN weaken from being left compressed for long periods.

Why do we keep needing to rehash this?

Because too many people assume that if something doesn't happen often and/or hasn't happened to them that is proof that it can't happen at all. And that belief is reinforced by people who understand the theory behind springs but who haven't fully thought through the implications of all the practicalities involved with spring design and manufacture.