Clarify: leaving Sig 232 mag springs compress.

[Ignition Override]

One 'camp' with rifle discussions always says that wear on springs is only caused by compression then spring extension. If a seven-rd. mag is only loaded with six, this would seem to reduce the chances of losing some tension.

I can't quite understand how long-term compression, the few exceptions being during a little practice, would Not reduce the spring's strength, tensile or whichever engineering term. It seems to me that changing the shape of an object eventually alters its properties.

 

[AK103K]

I wouldnt worry about it. I carried my P230s fully loaded, and they stayed that way until they were shot/retired. Same goes for a few spare mags.

The remaining P230 I have now, has been shot regularly since the mid 90's, and I have yet to replace a mag spring in any of the half dozen or so mags I still have, a couple of which are still loaded.

 

[Walt Sherrill]

I can't quite understand how long-term compression, the few exceptions being during a little practice, would Not reduce the spring's strength, tensile or whichever engineering term. It seems to me that changing the shape of an object eventually alters its properties.

You might try a search here on the forum for some very complete and technical explanations. A couple of engineers, including a metallurgist, have contributed to the discussions. Look up MAG SPRINGS, RECOIL SPRINGS, SPRING LIFE, etc. But here's a summary:

Long-term compression is ONLY a problem IF the spring, when the mag is fully loaded (i.e., loaded as far as the designers want it compressed), is at or near the spring's elastic limit. Some mag/gun designs never allow the spring to reach that point of compression, other mag/gun designs push that limit, to give you smaller guns holding more rounds, etc.

But...any material pushed to it's elastic limit tends can degrade very quickly -- whether it's steel, rubber, wood, or polymer, etc.

I owned a lot of CZs over the years, and during those years I found that the springs in the 10-round mags were the same springs used in their 15, 16, and 17 round mags. The spring is the same, but the work performed with a single full spring compression is quite different from one type of mag to another. Compress the spring once in a 10-round mag, and it's roughly done only 60% of the work done by that same spring in a 17-round mag. And when the spring in that 17-round mag is fully loaded, it's much closer (or maybe even beyond) that spring's design (elastic) limit.

Wolff Springs, on their site (in the FAQ area) suggests downloading a hi-cap mag a round or two if stored for long periods. (I suspect the same might be true of some of mags in sub-compact guns, where they try to get more rounds into smaller grip sizes.)

If a spring is properly matched to the job, working the spring won't greatly shorten it's life. That's why tappet springs in cars typically outlive the rest of the engine: they're stout springs; but the engineers who decide what's needed make sure the design doesn't push them to their elastic limit!! Those tappet springs may compress and release many, many millions of times over the life of the car and tappet spring failures are rare. If cycling alone could kill a spring, we should have had all sorts of spring deaths over the last 50 years in car engines alone. We haven't. The same sort of thing can be seen in a 7-round 1911 mag: it's a very forgiving design that doesn't ask the spring to do too much. Examples have been cited of 1911 mags kept fully loaded for several generations, without failure. More than one 1911 owner I've talked with has mags that they've used for years without having to replace the springs.

With most mags it probably won't matter whether you leave the mags fully loaded, or how much they're used/cycled -- but with some hi-cap mags (or mag or recoil springs in sub-compact guns) you may see mag springs weaken more quickly than expected.

 

[KevininPa]

I've owned a......

........Sig P232SL for years now. Mags are always loaded full. Never a glitch. Even though it's not in the rotation as much as it used to be, it still gets shot at almost every range session. No problems.

 

[Dragline45]

This is been discussed several times, it is perfectly fine to leave your mags loaded, especially with a single stack mag like a 232.

As Walt said

Long-term compression is ONLY a problem IF the spring, when the mag is fully loaded (i.e., loaded as far as the designers want it compressed), is at or near the spring's elastic limit. Some mag/gun designs never allow the spring to reach that point of compression, other mag/gun designs push that limit, to give you smaller guns holding more rounds, etc.

You will typically only see this in double stack mags for compact guns where they try to squeeze in as many rounds as possible. Like I said though, for your single stack 232 mag, you have absolutely nothing to worry about.

 

[Aguila Blanca]

I can't quite understand how long-term compression, the few exceptions being during a little practice, would Not reduce the spring's strength, tensile or whichever engineering term. It seems to me that changing the shape of an object eventually alters its properties.

If you keep your car for several years and never overload it, do you expect the springs to sag, or do you expect them to keep the car at the original height? Most cars today use coil springs on all four corners, and that's what a magazine spring is. Walt's valve spring analogy is an even better example.

It is long-term flexing that wears out springs, due to work hardening and metal fatigue. Beyond that, simple compression can't change the properties unless you exceed the yield strength of the steel -- which you can't do if you just use the spring as designed.