Mag Springs

there is no problem leaving magazines full.........it is the action of the spring expanding and contracting that wears them out......not leaving them compressed.

If the springs were made from high quality spring steel and correctly tempered you won't have any problems. The issues you are hearing about are almost always due to manufacturers that are using junk springs that are poorly made. With a quality spring leaving it compressed (within its working limits) will not cause it to lose tension. Another problem is double stack hi cap mags which unfortunately will place the spring in an overcompressed state to get the last couple of rounds in. These springs will fail if left fully loaded because they're being forced to perform beyond the limits of the spring. If you download them by two rounds most will last as long as a good single stack spring made from quality steel. I would always rather have a reliable mag with less rounds than one with a few more rounds that will have a short service life. Any time you have to use a loading tool and a lot of effort to insert the last few rounds then your spring is almost certainly being compressed beyond reason.

Full mags are not a problem.
2 things cause problems for springs. over compression and cycling.

My son has had numerous problems with Beretta 9mm magazine springs on his military side arm....issued ones are junk. Sent him new high performance ones from Brownells. You'd think our service men and women deserve better.

Rembrandt
My son has had numerous problems with Beretta 9mm magazine springs on his military side arm....issued ones are junk. Sent him new high performance ones from Brownells. You'd think our service men and women deserve better.

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^^^^
Got enough Chinese borrowed dollars to bail out European banks but won't spend on our own??? It's BULL, but I digress...

If you have springs that aren't strong enough to push rounds up for feeding, the spring is either so worn from thousands of cycles or it was junk to begin with. Compression/De-compression cycles kill springs, just like the one on your garage door opener. Leave your garage door closed forever and the spring will last forever. Over compressing beyond their specs will also kill them. I still lighten the mags for my nightstand gun by 1 or 2 rounds - old habit I guess.

weakened to where there gun would not feed.

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Usually the first symptom of a weak mag spring is the slide lock stops working on the last shot.
The empty mag doesn't have enough power left to push it up.

rc

Yes, I've seen it happen. Both with mags that are seldom used for any actual live-fire, as well as mags which have been heavily used.

I've seen quite a number of private owners (non-LE) bring their pistols to training range sessions and experience feeding problems due to weakened mag springs.

When I've asked most of them how often they use those guns & mags for practice, the most common answer has been that they seldom shoot for practice, unless preparing for a CCW qualification, and just leave the mags loaded (sometimes for years at a time). The significant number of such non-LE folks I've worked with over the years seem inclined to do very little practice. Not what you might call "frequent shooters".

Considering the number of folks who have experienced this sort of problem in classes where I've either been helping teach or teaching, I'm no longer surprised when a course of fire is repeatedly interrupted because someone has a mag or two with weak springs in a pistol they've owned for some years.

Naturally, there's also a number of other issues that occur which cause many of these folks feeding & functioning issues, but those are easily identifiable as not being related to weakening mag springs.

I've often discussed this issue with other firearms instructors over the years and have heard similar experiences related.

As has been mentioned, the quality of the spring used is important, and it's not hard to envision that some springs might be of lesser quality than others, or might have been originally manufactured at the "lighter" end of their normal specification for strength/tension. We expect a lot for relatively inexpensive mag (and recoil) springs.

Another consideration is that not everyone seems to care about cleaning and maintaining their mags. I've seen some really nasty & grungy mags come through the ranges. It's not surprising that even a mag spring with some useful service life left in it might have a problem functioning normally if the mag body is contaminated with fouling and gummy residue from owner neglect and/or abuse over the years.

As we were told in the Sig pistol armorer class, the pistol isn't clean unless the magazines are also clean.

While not quite the same subject, I might also mention that I've seen quite a number of folks who try to use mags in which the mag springs have been improperly installed. Mag springs which have a definite top/bottom orientation and which have installed upside down, or those which have been installed backwards, often tend to give the owners occasional issues.

I've also noticed over the years that some of the major manufacturers of service pistols have been recommending that armorers replace mag & recoil springs increasingly sooner, sometimes regardless of how much use they may receive.

Just my thoughts.

I keep hearing about not leaving mags filled,

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Stop listening to those people

Drail said:

If the springs were made from high quality spring steel and correctly tempered you won't have any problems. The issues you are hearing about are almost always due to manufacturers that are using junk springs that are poorly made. With a quality spring leaving it compressed (within its working limits) will not cause it to lose tension. Another problem is double stack hi cap mags which unfortunately will place the spring in an overcompressed state to get the last couple of rounds in. These springs will fail if left fully loaded because they're being forced to perform beyond the limits of the spring. If you download them by two rounds most will last as long as a good single stack spring made from quality steel. I would always rather have a reliable mag with less rounds than one with a few more rounds that will have a short service life. Any time you have to use a loading tool and a lot of effort to insert the last few rounds then your spring is almost certainly being compressed beyond reason.

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I was right with you until the bolded part. What you're saying is that magazine designers do fine with single stack magazines, but when it comes to double stack magazines they can't design a proper spring?

I disagree. Designers know the stresses placed on their springs, and specify length/spring constant/coils accordingly.

I've got two Glock 20 double stack magazines that I've kept fully loaded for the 6 years I've owned the gun. It's still just as hard to load the last round as it ever was, I can tell you.

If the right steel isn't used for the application, any spring will fail. Properly made magazines should have no problem being fully loaded, and staying that way -- old wives tales notwithstanding.

It's not that it "can't" be done but sadly it frequently is not done. The marketing boys want to be able to advertise how many rounds you can cram in their mag. And consumers have been completely brainwashed into believing they "need" all those rounds. In today's world the product doesn't have to last and or even work very well - it only has to sell large numbers. It is almost incredible how many years people survived with those crummy 6 round revolvers and 7 round 1911s.

Drail said:

...It is almost incredible how many years people survived with those crummy 6 round revolvers and 7 round 1911s.

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And muzzle loaders...

And flintlocks...

And bows and arrows...

'Tis called progress, my friend.

No, actually this is more about marketing than progress. But I see where you're coming from.

Drail said:

No, actually this is more about marketing than progress. But I see where you're coming from.

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I don't really agree. The 1911 was an improvement over the SAA because of it's more rapid rate of fire, and ease of reloading. The .45 ACP is certainly not more powerful than the .45 Colt, so knockdown power wasn't the reason why the 1911 became more popular. It IS more effective than a .38 revolver, but is also easier to reload than a revolver - thus an improvement, and not just a good marketing strategy.

Fast forward a few decades (quite a few) to guns that hold 15 or more rounds. While I've never encountered a pack of mountain lions I needed to shoot all at once, there are certainly instances where a higher capacity gun could save your life -- for instance, if a pack of feral dogs came after you.

Likely? Not for me. I am glad to have the firepower there, though.

Going from single stack to double stack is progress, cramming that one extra round in a mag is marketing.

The point is properly designed mags with quality components, regardless of capacity. Deciphering which manufacturers do not abide by that criteria is the real question.

Drail said:

Another problem is double stack hi cap mags which unfortunately will place the spring in an overcompressed state to get the last couple of rounds in.

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Correct re: over compression.... as to double stack I wouldn't know. I have 5 BHP mags with never a problem, but they're all 13 rounders, so maybe your later advice about down loading is "built in" as it were.

Drail said:

These springs will fail if left fully loaded because they're being forced to perform beyond the limits of the spring.

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You've got that about 75% correct. The damage is done at the time of over compression, not by leaving the mag loaded. The damage gets progressively worse with each over compression event, but leaving it over compressed should do no more damage that pushing it that far in the first place.

But the general gist I definitely agree with. Buy good quality mags and don't worry about leaving them loaded.

#7
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Leaving magazines loaded.

7. It appears that in the vast majority of cases magazines continue to function perfectly after being left loaded for extended periods of time. I have personally left rifle and pistol magazines loaded for up to 10 years and they worked fine when put to use. I have heard others speak of getting the same results after leaving magazines loaded even longer than 10 years.

jdowney said:

...You've got that about 75% correct. The damage is done at the time of over compression, not by leaving the mag loaded. The damage gets progressively worse with each over compression event, but leaving it over compressed should do no more damage that pushing it that far in the first place...

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This isn't how metal deformation works. Look at a stress/strain curve, and you'll see that once past the yield point the metal will be in a deformed state.



Springs for magazines are made to be preloaded, so once it's deformed, it will probably still contact the top of the magazine when empty, but not with as much force. This is why the last round or two won't load properly, if at all.

If a magazine was made with an improper spring, once it's compressed too far, it will never have it's full force again. You could try pulling it out to give it some more length, but the metal has been fatigued and will now be brittle -- and will break much sooner.

There is a wealth of scientific information available on this subject, which it would be a good idea for those interested to look up. Anecdotal information or friend-of-a-friend stories don't really help clear the waters much.