mag's loaded or empty?

[jal910s]

O.k., I want to keep my gun handy for home defense, but I have a question about the mag spring, can it be damaged by keeping the mag loaded? mine are 15 rd mags and can easily fit them all, but i only leave 10 in because i don't want to leave too much stress in the spring, or am I just overly paranoid?

 

[PDL]

Hi and welcome to the forum.
If you do a bit of searching around, you'll find plenty of answers to this question.
To summarize some of that, the actual stress on the spring is caused more from loading and unloading rather than being compressed for long periods of time. Some examples were given about WWII loaded mags that still performed. I'm sure you'll hear more on the subject.]
One thing you've got to watch is bullet push back if you chamber and unload the same round over and over.

 

[FourEyez]

I have no technical experince to tell you one way or another, however my brother, a former cop suggested not maxing out the mag leaving less then half of its max cap to avoid "spring memory".

Maybe someone with exact info will chime in.

good luck

 

[sbeduckman]

Hi and welcome to the forum.
If you do a bit of searching around, you'll find plenty of answers to this question.
To summarize some of that, the actual stress on the spring is caused more from loading and unloading rather than being compressed for long periods of time. Some examples were given about WWII loaded mags that still performed. I'm sure you'll hear more on the subject.]
One thing you've got to watch is bullet push back if you chamber and unload the same round over and over.

+1 to the above. Unloaded or loaded, doesn't really matter. It's the process of being sprung and unsprung repeatedly that kills springs. I'd fill them full and leave them that way...I do. Some people will tell you to rotate them every six months or so. I've read tensile strength reports from people who engineer springs; most will tell you it doesn't matter if they are compressed or not as far as longevity is concerned.

 

[ImprovedModel56Fan]

I am not a metallurgist or an engineer, and I only "know" what I've read and what people tell me, and what very little I've actually experienced myself. A trusted friend told me about a 1911 mag that came back from World War ONE, fully loaded, but separate from the 1911 that disappeared from the luggage of the GI who brought it back. In the early 60's, it was given to my friend, who inserted it into a 1911 and fired all seven rounds in the normal manner.

I have since read one gun-rag article on springs that hints that Colt metallurgists are not surpassed by those of any gun manufacturer. Whether the mag my friend ran across was a Colt is not known.

FWIW.

 

[Dragonfly]

I don't think it's the loading and unloading that cause springs to take a set. It's been almost 22 years since my metallurgical engineering course (and I'm not working in the field now) so I'm admittedly a little rusty but if I remember right there are three failure modes for springs:

• Fatigue Failure: This is when there is a complete breakage of the spring, Usually starts a a flaw in the metal and then and the spring works the crack progresses enough that it can't withstand the stress and the spring breaks. I've never heard of a mag spring breaking in this way.
• Failure from exceeding ultimate stress: This would be is a spring is stressed (or compressed I suppose in some cases) beyond its designed capacity--like if you grab a spring and stretch the heck out of it--it doesn't return to its previous size. But cycling a spring in a magazine does not subject it to stresses that exceed its design stress so this isn't the cause either.

which leaves...

• Creep: This is a phenomenon where some materials (plastics, especially, but also some metals) deform when they're subjected to loads at less than their maximum but still slowly deform (or they take a "set") over time. This is what causes some springs to lose their strength. But, it's static, not dynamic, force (I think) that causes creep (like a car sitting on its springs)--loading and unloading them wouldn't cause this, but leaving them loaded could. Obviously, though, most magazine springs are designed so that creep is not a problem.

It's certainly possible that I'm misremembering something but my hypothesis is that if a spring is going to take a set it's leaving it compressed that'll cause it, not cycling it. Any thoughts?

 

[kona0197]

What is "bullet push back" ?

 

[P&R Fan]

"Bullet push back" is when you load the same round over and over, probably in a carry gun, and the bullet sinks deeper in the case. It is supposed to cause higher pressures when fired. I have several rounds that have done this in my Glock .40s. I have shot some without problems though.

 

[Big Lou]

Leave them loaded! I've heard the same argument (load14 rds. in a 15rd. mag, etc.). I can only speak from carrying them for almost 30 years on the job. I never had any problems with fully loaded factory mags. They work!

Just rotate the ammo every 6 months or so. You'll be fine.

 

[kona0197]

Is it wise to cycle ammo every week?

 

[P&R Fan]

If it is I'm not wise. It would be extremely expensive for one thing at today's ammo costs. Ammo can last a VERY long time if not subjected to harsh environments.

 

[jammer45]

If it is I'm not wise. It would be extremely expensive for one thing at today's ammo costs. Ammo can last a VERY long time if not subjected to harsh environments.

Isnt that the truth LOL. I was looking at some ammo boxes I have had for years now I use when I reload ammo and I have some pics of my old reloading bench with some reload equipment. I have a box from a brick of 1000 large pistol primers $12.50 a box of CCI small pistol primers $10.50 and a box of CCI Lawman 200gr JHP $11.25 WOW how times change and I have a plastic bottle that had 1Lb of No.#7 powder in it the price on it was $17.00 LOL I can't believe how much things have went up its not like the bullet manufacturing has changed significantly in the last oh say 50+ yrs LOL

 

[kona0197]

I meant is it wise to take the ammo I had loaded in the mag out and put it back in.

 

[tpd223]

I meant is it wise to take the ammo I had loaded in the mag out and put it back in.

No, it is not. This leads to the rounds being scratched and nicked from being placed in and out of the mag, which can lead to misfeeds during the firing cycle.

When we first got S&W 9mms in 1989 we were told to unload our mags on the weekends so the springs could "rest".

This was complete BS. A spring is metal, not a muscle, it can't get better or heal itself, it either works or it doesn't.
If a spring goes bad, or you think it's going bad, trash it and get a new one. Mag springs are normally like $3-5 or so, very cheap life insurance.

FWIW, I know first hand of ammo being loaded in a 1911 mag from WWII and being fired 60 years later.
I also know my S&W mags were constantly loaded while we carried that system at work, some of my mags were loaded for 20 years and only cycled when the ammo got fired off, the mag would be cleaned and the mag reloaded.
I had a couple of misplaced 5906 mags that were loaded for better than ten years, fed without issue when I banged off the ammo in them.

 

[NE450No2]

I have used several different magazines, that have been loaded for several years, and shot, for several years with no problems.

If they are not "on the person" carry, then down loading them a few rounds might not be a bad idea....

But some magazines I use on a regular basis have been loaded/shot for 30+ years with no problems...

I do not worry much about it.

 

[kona0197]

I would sure like to know where you can get cheap mag springs. Wolf Springs wants around $20 for them.

 

[Bob R]

I would sure like to know where you can get cheap mag springs.

I don't know if "cheap" is the operative word, but you can get Wolff springs from Brownells. For example a 3 pack of Wolff extra power springs for my Delta Elite mags ran about 15 dollars or so.

bob

 

[photocosmo]

loaded mags...

My main problem is that when I find that I have loaded magazines I can't wait to UNload them (at the range)!

 

[szuppo]

Load them up to full capacity and forget about them. Don't cycle your ammo every week or your magazines every other day.
Just leave them alone, other then a visual inspection and they will be fine for a long, long time.

 

[fyimo]

I leave mine loaded for very long periods (years) and they always function as they should.