spring degradation in loaded magazines controversy - American Rifleman

In a properly designed spring system, it should never even be able to compress the spring enough for significant change in internal tension/spring force. If you can, well, you broke the spring.

This isn't rocket scientist. Buy a statistically significant number of springs. Compress and leave compressed 1/3, cycle 1/3 and leave 1/3 as a control group. At set periods, measure the actual spring force constant over its intended stroke.

Corrosion and stiction are the real issues. Not static spring fatigue.

btw: in every magazine i've ever dealt with, the spring is compressed even if it is 'empty'. Not always true with a clip.

My aunt Zula has had the hammer cocked on her early-century .32 Long Colt Hand-Ejector, since Uncle Harry died in 1979. I know that hammer spring must be getting tired. Still aint nobody volunteered to stand in front of it.

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Ask her if you could check it out and offer to clean it up. I bet it would still work.

Don't know about the modern stuff but I do know that the Luger I inherited from an uncle 10 years ago had a weak magazine spring. Got a new aftermarket Luger magazine and the problem was solved. That gun had a loaded mag in it almost constantly from when he brought it here in 1945 until about the early 60's when it took up residence in his closet. My late aunt probably wanted it ready at all times ever since the early 50's when my uncle was away on an overnight business trip and she was home alone with their 2 small sons in a rented house in a semi-rural area. She woke in the middle of the night to the sounds of someone breaking in downstairs. She opened the upstairs window and fired a couple rounds into a snow drift and called the police. The guy was never caught but they said by looking at his tracks in the snow leading away from the house it was obvious he left in a very big hurry. So for 10 years or so after that the mag was always kept loaded just in case something like that happened again.

Lordy. I think it's time to riff this thread.

http://www.youtube.com/watch?v=XJD0GTwLkVM

For those who have their minds made up, facts are irrelevant.

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This. I give up

There was a case where someone in Europe found a Sten gun and several magazines hidden since WWII and turned it over to the police. The police fired up all the rounds without a problem and I think they put the gun in a museum. I am sketchey on the details but the point is that after 60+ years the thing worked and the magazine springs did not take a set.

Only .40S&W mags suffer from spring fatigue due to long-term compression. Mags built for all other calibers are ok.

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Nah, not the mags.

It's the faster cycling slides that may start to outrun the mag springs before it might happen with lesser recoiling calibers. It's not hard to hear of instructors & armorers who see 9mm guns run longer on mag & recoil springs than .40's, for example ... (on the same rated springs, in guns of both calibers which share spring assemblies).

Of course, the harder recoiling calibers (.40/.357) are also a bit harder on recoil springs, which might (or might not) be more noticeable, sooner, in the guns which share the same recoil springs for both 9 & .40.

As far as very old magazines which have been left loaded and unused for decades? Sure, not hard to find instances where the old mags & springs still worked. The thing is that's it's not hard to find examples where the springs in the old & fully compressed mags were too weak to work, too. Toss a coin, I suppose, and hope for the preferred outcome.

It's interesting and "noteworthy" when an old mag stills works. We like to read about such things. Not so much when the old ones don't work, though. Ignore that one and wait for one that better suits our hopes, maybe?

When it comes to range/leisure/sporting pistols and their magazines ... not much of a "loss" if a spring is suddenly found to be too weak to work "when desired".

A bit more problematic if it happens in a gun that's dedicated to a defensive role, though. May not get a "do over".

Folks ought to be able to suit themselves (as long as it's not an agency-owned weapon) ... and perhaps acknowledge that their expectations may not always match life's possibilities.

I prefer to reduce my exposure to unnecessary risk, and liability, myself. That's just me, though.

What effect does slide velocity have on a magazine spring? The slide doesn't accelerate the magazine spring at all, and the only thing that drives the next round in the mag upward is the magazine spring, not the slide.

My guess is that it may be one of those Ford Vs Chevrolet things,but for me I started carrying auto in the 70's and still do so I always rotate my clips.My duty weapon sometimes I only had 3 magazines so on my days off I unloaded all 3 mags.I have a small auto in a drawer next to my bed I keep 1 mag. loaded and the other empty. I change mags about every 2 weeks.In 42 years of doing this I have never had any problems with mag springs. I don't know if it works I just feel better about it.

"What effect does slide velocity have on a magazine spring?"

The mag spring has to maintain enough pressure on the follower to keep presenting rounds high enough for the returning slide to pick up. If the mag spring can't keep up, the slide returns to battery with an empty chamber.
The faster the slide velocity, the less time there is to feed the next round.

Some HGs, like those used in IPSC Open Division, have an incredibly short cycle time. If the mag spring is weak (or the spring is slowed by dirt or rust) it will not keep up with slide velocity, especially when presenting the last couple rounds.

still say leaving a mag compressed is no worse than repeated loading and unloading. fatiguing the metal is more harmful than just compressing it

The word "saga" is derived from old Norse describing spring sag. true story

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Unless this is a joke, I'd like to see the back-up on that idea.

Most of what I find says the same basic thing as Wiki; "Saga" is a word originating from Old Norse or Icelandic language. Saga is a cognate of the English word say: its various meanings in Icelandic are approximately equivalent to "something said" or "a narrative in prose", somewhat along the lines of a "story", a "tale", or a "history".[1]
or .... In Norse mythology, Saga is the goddess of poetry, poetic arts and history. Every day she drinks with with her father Odin from golden goblets in her hall Sokkuabekk. She is identified with Frigg.

Hasn't this subject been beat into horse-hamburger over the decades? 'American Rifleman' must be hard up for non-stories.
.

Personally I think leaving a magazine loaded forever will weaken the spring. My question is: Does it matter? Who only has one magazine for their self defense weapon?

Just cycle your magazines every week or two and you'll be fine for a long time. When the gun starts to have some malfunctions, then replace the springs.

The mags on several of my semi-autos are all fully loaded. Problem is they never stay that way for long as I'm at the range on a weekly basis. I do worry as the mags for my AR are loaded up and I dont shoot it very often. More of a Trap and pistol shooter these days.

pockets said:

Unless this is a joke, I'd like to see the back-up on that idea..

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Yep, that right there was an attempt at humor.

I keep all my magazines loaded to the tippy top. No problems and with some being many decades stoked and used.

twofifty said:

"What effect does slide velocity have on a magazine spring?"

The mag spring has to maintain enough pressure on the follower to keep presenting rounds high enough for the returning slide to pick up. If the mag spring can't keep up, the slide returns to battery with an empty chamber.
The faster the slide velocity, the less time there is to feed the next round.

Some HGs, like those used in IPSC Open Division, have an incredibly short cycle time. If the mag spring is weak (or the spring is slowed by dirt or rust) it will not keep up with slide velocity, especially when presenting the last couple rounds.

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Ok, just wanted to clarify that it wasn't believed that slide velocity had anything to do with any process of magazine springs weakening.

hardheart said:

Ok, just wanted to clarify that it wasn't believed that slide velocity had anything to do with any process of magazine springs weakening.

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twofifty's explanation was more clear than mine.

Whether a spring takes a set or not is determined by the stress level in the material. Most magazine springs are coil springs, which are helically wound torsion bars. They provide force through the torsion (twisting) of the spring material as it is compressed. Some, such as drums and a few high-cap aftermarket pistol mags, use a constant-force flat wound spring - similar to that used in a lawnmower recoil pull-starter.

It's possible to build coil springs that can be fully compressed to coil-bind that will not degrade. Some manufacturers may use different materials (lower yield stress) that will deform at lower loads while others may use higher quality steels. A high quality spring can be loaded to coil-bind forever with no effects.

Layman's guide to coil spring deformation:

http://springipedia.com/compression-stress-spring.asp

It really depends on what oil you use.

I found an old box containing 4 AK47 magazines loaded to 30 rounds - lost it during a move, discovered it three or four years later. Three of the four magazines failed to function correctly.

Fortunately, AK47 mags are cheap, and I didn't really care.

I had some MecGars loaded with 17 rounds of 9mm, stored for 5 years straight for my Ruger P95, took it out recently, they still run fine.

I've got some AK-74 bakelite magazines that have been sitting full for 5 years now. Gonna try those out one of these days. Maybe I'll wait another 5 years.

I know for a fact that extended time while loaded does weaken the springs for at least some types of magazines. I've had two different types of hand gun mags do this, but it did take several years of storage. One of them was a high quality Wilson Combat 1911 mag. With almost no use over a period of 2 to 3 years, but loaded, the mag was no longer able to even engage the slide stop when empty.

Springs *might/* last a long time, but now I replace mine every two years, regardless of firing schedule (unless they are unused, unloaded of course).

I understand there are many variables.

If one were to change out springs on loaded magazines...roughly how often should this be done?

in every magazine i've ever dealt with, the spring is compressed even if it is 'empty'. Not always true with a clip.

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This is also a good point, they're usually compressed to some degree. Are we to start unloading our magazines of their springs when not in use. That could be a whole new Magpul product line. Spring storage cases.

Cynicism pumps to full...

If I sold mag springs, I'd easily convince myself that all mag springs should be switched out at least annually then preach that to my potential customers. Ka-CHING!!

Cynicism pumps to idle...