How long can mags be left loaded?

C

Cullen

New member
Hi folks,
Another important question regarding loaded magazines. In a recent thread regarding how much ammo to have on hand, I remember reading among many opinions that it was good to have at least 50 rounds for the HD weapon ready in magazines.

Okay, two questions:
1. Where can I find QUALITY mags for my P229? I don't want any cheap crap.

2. How long is it safe to leave magazines loaded for? I have been told that leaving a mag loaded fully for long periods will cripple the magazine spring, leading to feed failures. I've been told that loading only halfway will prevent this. Is this an old-wives tale?

Cullen

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Those who say Science disproves the existence of God understand neither Science nor God.

We scoff at honor and then are surprised to discover traitors in our midst - Edmund Burke
 
1. Where can I find QUALITY mags for my P229? I don't want any cheap crap.

Now hold on, are you looking for preban standard capacity or for postban? If you're looking for prebans factory mags can be found by scouring the Web and checking Shotgun News, average price for NIB mags is about $125. Mecgar, OEM supplies for SIG Arms, is the only other option. I've yet to see NIB preban MecGars, but I was told you can expect to pay about $75 for these. If you mean postban factory mags www.midwayusa.com has them in stock, but they're too expensive at $35 so I prefer to go with MecGars $18, and they work equally well.

2. How long is it safe to leave magazines loaded for? I have been told that leaving a mag loaded fully for long periods will cripple the magazine spring, leading to feed failures. I've been told that loading only halfway will prevent this. Is this an old-wives tale?

Forever and a day. ;) Download one round if you want to reduce strain, but the springs are designed to be kept loaded. I usually rotate mags evey two months and replace springs every few years. A buddy of mine that lives in the Third World (does anyone say this any more?) has an IMI Jericho with two mags he keeps fully loaded and has done so for about six years now, he's yet to report a problem. His economic situation prevents him from buying more mags.


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So many pistols, so little money.
 
Thanks Tecolote
Clarification: do the standard cap mags hold 12 or 15 shots? (If 12, then I'll never waste the money on std caps; even if it is 15, I'd rather have a half-dozen 10 shot mags and money left over in all likelihood.) Just curious.

Thanks for the tip on leaving mags loaded. That's a load off my mind. Now I'll leave both on my factory mags loaded instead of just one ( I was "rotating" one mag at a time ).

Cullen
 
40SW P229 standard capacity mags hold 12 rounds. I'm with you, I cannot see myself spending a $100 for a few extra rounds. if I had the money, which I don't, I would invest in a few prebans for a P228.

For SIG Sauer questions I've also found www.sigforum.com very helpful.

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So many pistols, so little money.
 
<BLOCKQUOTE><font size="1" face="Verdana, Arial">quote:</font><HR>Originally posted by jtduncan:
I swap loaded mags every week.[/quote]
Every week might be a little excessive. While keeping the magazines loaded all of the time is not good. Constantly (every week) loading & unloading the magazines also puts a strain on them as well.

I personally load them to 80% of capacity (a 10 round magaizne is loaded with 8, a 15 rounder gets 12, etc.) and rotate them every other month.

TFL-flame.gif
Share what you know, learn what you don't
TFL-fud.gif
 
FUD is right on the money. The constant loading and unloading will cause the spring to fail. Keep your weapon loaded to capacity, purchase a few replacement springs in the event that your magazine goes belly-up.
 
Speaking of which, does anyone know where to get extra mag springs for HK USPs? Or any other parts for the darn things, for that matter?
 
Heh. I love this topic. Especially since we hear so much contradictory info on it:

Guy_1: I change my mags every week.

Guy_2: I never change my mags.

Guy_3: I know a guy who found a colt 1911 frozen for 60 years in a glacier in alaska and the magazine fed perfectly!

Guy_4: I had a failure to feed due to overstressed mag springs and was killed in a gunfight!

Guy_5: You?

Guy_4: Well, I got better.

Heck. I have nothing new to add, thats for sure. I change my mags every once in a while. I _do_ like having an extra mags on hand for whatever guns I keep loaded, and once in a blue moon, in a scandalously unscientific and disorganized fashion, I swap them out.

It IS a great question, though, and one I'd LOVE to hear answered in a scientific manner.

Mike



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"A human being should be able to change a diaper, plan an invasion, butcher a hog, conn a ship, design a building, write a sonnet, balance accounts, build a wall, set a bone, comfort the dying, take orders, give orders, cooperate, act alone, solve equations, analyze a new problem, pitch manure, program a computer, cook a tasty meal, fight efficiently, die gallantly. Specialization is for insects." -Robert Heinlein
 
I can understand how keeping a mag fully loaded will eventually fatigue the spring. But how does loading and unloaded a mag every week result in spring failure?

I'm asking because that's what I tend to do and if it really is bad for the spring I need to stop!
 
Once again, I don't think anyone really knows. Someone here with a metallurgical background or just plain old experince with metal might be able to explain howloading or unloading mags can cause fatigue (and how this differs from just plain using the gun), but the real question that needs to be answered is the end result: what is the best technique for maintaining spring 'life?'

There is so much anecdotal evidence (AKA "war stories") that is mutually contradictory that it probably doesn't make much sense to listen to it. For each old gunner espousing switching mags theres another saying don't do it. Who is right? Who knows?

I'd like to do a scientific mag test. Go out and buy about 1000 magazines take 10 years to perform the study.

Anyone who wants to contribute $$$ to this cause, please feel free. I'll get back to you next decade, and make your checks payable to...

;)


Mike

PS Also, to anyone who wants to contribute, I have a bridge to sell as well. No checks please; cash only, in small bills.

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"A human being should be able to change a diaper, plan an invasion, butcher a hog, conn a ship, design a building, write a sonnet, balance accounts, build a wall, set a bone, comfort the dying, take orders, give orders, cooperate, act alone, solve equations, analyze a new problem, pitch manure, program a computer, cook a tasty meal, fight efficiently, die gallantly. Specialization is for insects." -Robert Heinlein
 
eagle-eyes, this is how it was explained to me: Take a paperclip and open it up and close it again. Do that several times and it will break. The springs in a magazine are obviously are of a higher quality and you're not exactly bending them out of shape & back again but you are putting pressure on the joints/elbows of the spring and the same basic concepts apply. I use to load up my magazines in the morning and unload them at night and in under half a year, they had to be replaced. I now unload them every couple of months and only load them to 90% of capacity (meaning I leave one or two bullets out) and I have original magazines that are more than a dozen years old and still function flawlessly. This is just my persoanl experience and others may have different points of view.
Share what you know, learn what you don't -- FUD
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You asked a question about why the spring wears out?
It's been a long time since I've had any materials engineering classes so bear with me:
Metal is made of little crystals, right? They have a structure. When you stress the structure the crystals try to 'creep' into a new form to relieve the stress- to relax into a new organization. Hence, if you leave the spring stressed it will get weaker.
HOWEVER
THere are two regimes when talking about bending:elastic and plastic. In the elastic region when you bend it a little bit it pretty much returns to the original form. To borrow the paperclip analogy it's when you clip a small sheaf of paper.
Beyond that you hit the plastic region where, once it bends it STAYS bent, minus the length of the elastic region. When someone hits your car door in the parking lot it's in the plastic region! If you wrap a paperclip around War and Peace it isn't going to be the same!
There's the theory anyway. A well made spring should operate in the elastic region. As you extend and relax the spring you Do generate a type of friction, which raises the temperature of the spring allowing it to 'anneal' or relax faster. Bend a steel paperclip back and forth and see how hot it can get. Also, just the mechanical act of bending the structure forces it to try to relax.
How much does this affect the spring when you do it once? I have no idea, having never done experiments with one myself. If someone gets bored then go to your garage with a hammer, a standard mass, and a measuring stick. Bang on the spring at a steady rate and every 1000 whacks or so measure how far the spring deforms under the weight of the mass. Also, load up a magazine for a year at a time and then measure how far it deforms under the standard mass. Don't use the magazine otherwise because that will skew the results. Post when you have data. Just an idea :p
regards
 
<BLOCKQUOTE><font size="1" face="Verdana, Arial">quote:</font><HR>Originally posted by Coronach:
Heh. I love this topic. Especially since we hear so much contradictory info on it:

...

It IS a great question, though, and one I'd LOVE to hear answered in a scientific manner.

[/quote]

Well, think about other springs that you depend on. For one, think about the valve springs in your car, when is the last time you considered changing them? No matter where the engine stops, some of them are compressed, some are not. They last a lifetime in the typical engine... Personally, I've had magazines loaded for several years, and I've then compared the spring length and tension to new magazines. There isn't enough difference for me to get excited about, so I don't spend any time worrying about this problem.
 
I just like being quoted. makes me feel like a celebrity or something. ;)

Okay. I understand how compressing and releasing mag springs increases the stress on them. What I don't understand is how this is significantly different than the compression and release the gun sees in everyday use.

Lets say I go to the range once a week, fire a box of ammo, then load up my mag again and leave it that way until the next time I go shooting. If I do this for a whole year, I will have loaded and unloaded my magazine about 312 times. This is assuming one ten-round magazine.

Lets say the next year I go to the range, fire a box of ammo, load up the mag. Next week I shoot my box of ammo and swap out mags with a fresh mag.

Total mag loadings/unloadings has now risen to 364, divided between two mags. Even if you do this for two years (double the use since you're doubling the number of mags), its still only 364 reloads per magazine. This is an 16% increase in the number of times the magazine is cycled, but it halves the amount of time the spring is in its compressed state.

Naturally, there are problems with this calculation (how many of us use 1 ten-round mag? Many of us might not shoot a box a week while many of us might shoot a case a week. Many of us might use different magazines for carry ammo and for practice). This ain't no scientific test. ;) I'm just saying that I'm not sure I buy the 'added strain' argument.

I could be wrong, though. Like I said before...I have no idea whats good or bad for the springs. Feel free to poke holes in this argument. Logic tells me its probably a good idea to rotate the mags and let the springs rest a little. And thats what I do, and I really don't worry about it all that much.

Hey, here IS a very relevant question: Hicap mags are now illegal to produce. Are replacement springs for existing hicap mags still able to be purchased?

Mike

PS See? living proof that what I do must be good for my mags. I have not yet worn out a spring in my hicaps. ;) ;) ;)



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"A human being should be able to change a diaper, plan an invasion, butcher a hog, conn a ship, design a building, write a sonnet, balance accounts, build a wall, set a bone, comfort the dying, take orders, give orders, cooperate, act alone, solve equations, analyze a new problem, pitch manure, program a computer, cook a tasty meal, fight efficiently, die gallantly. Specialization is for insects." -Robert Heinlein
 
<BLOCKQUOTE><font size="1" face="Verdana, Arial">quote:</font><HR>Originally posted by Coronach:
I just like being quoted. makes me feel like a celebrity or something. ;)
...
Hey, here IS a very relevant question: Hicap mags are now illegal to produce. Are replacement springs for existing hicap mags still able to be purchased?
[/quote]

I quote people, just to make them feel good. :)

As for the other question, you can buy replacement springs for hi-cap magazines from a number of sources, Wolff makes them, try http://www.gunsprings.com/ and I think you'll solve your hi-cap mag spring supply problem. :)
 
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