Letting Your Magazine Springs Rest

Abraham · Post by **Abraham** » Mon Dec 03, 2007 5:25 pm

There are different schools of thought on this subject.

My understanding is this isn't necessary.

At least, not with modern magazines, such as those that come with Glocks, Sigsauer, etc.

What's your take?

PhilR. · Post by **PhilR.** » Mon Dec 03, 2007 5:31 pm

I don't "rest" my mag springs. I use them as they are intended to be used, and replace them when they need replacing. To me, they are a wear item, much like tires or brakes on your car.

PhilR.

tboesche · Post by **tboesche** » Mon Dec 03, 2007 5:41 pm

I keep two mags loaded for the defense pistol all the time. When I go to the range I use all 4 mags. When I reload for the trip home, I swap them out. Don't really think I need to, but it is something I have always done

KBCraig · Post by **KBCraig** » Mon Dec 03, 2007 6:10 pm

It's very simple: if they're not moving, they are resting!

Unloading and reloading them causes more metal fatigue than leaving them loaded. It's not debatable: it's just plain metallurgy. Check any freshman textbook in Engineering Materials.

Mike1951 · Post by **Mike1951** » Mon Dec 03, 2007 7:07 pm

This is from the Q&A section of C-Products, a top maker of AR mags.

Q: Chrome silicon spring versus 17/7 stainless?
A: Every spring will take a set when compressed. A 17/7 stainless spring in a 20 or 30 round magazine will take a set the first time it is compressed and will continue to do so each time the magazine is reloaded eventually losing its load. A chrome silicon spring will take a set the first time and maintain that load each time the magazine is reloaded.
Q: Will a chrome silicon spring rust?
A: Yes, initially it will develop a slight film which will not affect the function of the spring.

So I order all of my AR mags with chrome silicon springs. I have no idea what springs are in my pistol mags, but I fall on the 'won't take a set' side.

WildBill · Post by **WildBill** » Mon Dec 03, 2007 7:59 pm

I think this is an excellent topic. In fact, I was thinking of starting a post this afternoon about the same subject.

KB and Mike are right on. Abraham makes the statement about "modern magazines." I have read this term in several gun magazine articles, but I think that "properly designed and manufactured" is a more accurate description. One might think that all "modern magazines" are properly designed and manufactured, but this is not the case.

Any spring, antique or modern, made from wire of an inferior/ inappropriate alloy and that are not properly stress relieved will take a set. This is the type of spring that is probably responsible for people thinking that they must "rest" the magazine springs. No amount of rest is going to turn them into good reliable magazines.

mkim1120 · Post by **mkim1120** » Tue Dec 04, 2007 12:05 am

i hear a 50/50 split between people that say it is okay to leave a magazines always loaded, and those that say it is never wise to leave one constantly loaded.

my primary home defense is a g19 w/ a glock 33rd magazine.
i only load it up w/ about 22-25 rounds and try not to top out the magazine

i personally dont rotate magazines but being that most of my guns are about three months old i dont feel that is necessary to.

nuparadigm · Post by **nuparadigm** » Tue Dec 04, 2007 6:58 am

This topic was also discussed here:
http://www.texasshooting.com/TexasCHL_F ... spring+set

stevie_d_64 · Post by **stevie_d_64** » Tue Dec 04, 2007 8:44 am

Maybe I have just not seen it, but the phrase: "take a set" would that be similar to a spring developing a "memory" under say like a full load of rounds in a magazine???

Just curious...

There may be a convention of thought out there that magazines do over time and usage that the springs may also develop a stress or fatigue issue in the compression and release during operation...I see that as a problem towards the end of the springs lifespan, but only at the end...

To me the issue is a three part process with a "new" magazine...

- Break-in phase

- Optimal performance phase

- Older magazine starts to develop feeding problems

The last phase you'd probably be looking to either chunking the thing, or do the fun part and refurbish it...

I would imagine that the usage of a magazine only helps it work that much better because it doesn't or shouldn't sit in a "set" or compressed state for very long before it might be a good idea to get out to the range and work out a bit...

Just my take on this...

This is one thing I have discovered about the Bersa .380's...The initial performance of the factory magazines stink, for lack of a better term...Once you get it wrung out, they don't give you too many more problems...

And as for used magazines...They are a lot like used cars...You'll be making a lot of lemonade before you cruise in comfort...

dukalmighty · Post by **dukalmighty** » Wed Dec 05, 2007 10:13 pm

I remembe in the military before 30 round m-16 mags we had 20 rounders that we only loaded with 18 rounds to keep from compressing the mag spring and to aid in reliability IIRC

KBCraig · Post by **KBCraig** » Thu Dec 06, 2007 2:53 am

dukalmighty wrote:I remembe in the military before 30 round m-16 mags we had 20 rounders that we only loaded with 18 rounds to keep from compressing the mag spring and to aid in reliability IIRC

There are two variables in play. Over-compression, in your example, is stressing a spring beyond its limits. That has nothing to do with fatigue: exceed the limit once, and it's done. Fatigue is entirely different: it's cycles of compression and decompression. If you take that 20 rounder and load it with two rounds, then unload it, repeatedly, you will eventually exceed its limits, and it will eventually fail.

Technical note:
What I just posted is not technically accurate, and I exaggerated for effect. It would take much more than 2 rounds (and probably more than 18). Ferrous metals have a lower yield point, below which they will not fail no matter how many cycles are applied. Aluminum does not; no matter how small the load, if you repeat the cycle often enough, it will eventually fail.

Just wanted to be technically correct. If I erred on terms, you know why I switched majors from Engineering to Journalism 25 years ( ) ago.

Kevin