How often do you rotate mags?

A little quick research. Springs degrade in 2 ways.

Fatigue which is the result of cycling and is usually after 10's of 1000's of cycles. I don't think this is an area of concern for a magazine (more like for valve springs in a car).

And creep/relaxation which occurs from being under continuous load or compression. The amount of relaxation (as applies here) is a function of the load, temperature (not really valid unless your the guy that hides his ammo in the oven ;-) ), and time. So I would think storing a fully loaded clip over a long time would relax the spring. As the load on the spring as it compress is exponential, those last couple of rounds in the magazine will stress the spring the most. 8 to 10 in a 13rd clip would sound like a good choice. I'm happy with my 10 of 15 choice.

Some spring info here: http://www.lesjoforsab.com/technical-information/durability.asp

Incidentally, reducing the rounds would be less stress on deforming the ammo as well. Good point.
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Engineer, Scout Leader, Motor head, Shooting sports enthusiast
 
Interesting info. My favorite analogy on springs & mags is the garage door assist spring. It occasionally breaks due to cycles of opening & closing and will not experience stress when just sitting there.

pgdion
A little quick research. Springs degrade in 2 ways.
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I have heard that under pressure the case will start to deform and can cause problems with chambering. I shoot often, but not the SD rounds, what is the longest you would keep ammo loaded before using it and then replacing?
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Absolute NONSENSE!!!

I just shot up some Corbon 40 s&w ammo that had been sitting loaded in some mags for 5 plus years. Ammo was fine, mags were fine, everything worked great. I just thought it was time to load up some new ammo in the mags. Corbon's 40 bullets shed their jackets too easily anyway so... ;)
 
But not many comments on the ammo, I have heard that under pressure the case will start to deform and can cause problems with chambering.
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There is no issue with normal ammo deforming while sitting in a magazine. If you have to eject and repeatedly rechamber the same round, you can run into issues with setback and primer sensitivity.

Setback is basically the bullet getting pushed slightly deeper into the case with repeated rechambering so that when it is fired, the pressures are higher than normal.

Primer sensitivity issues due to ejecting and rechambering occur in firearms with free-floating firing pins. The pins slightly dimple the primer with each chambering (M16 family of weapons being the most common example of this) and with many repetitions this can result in the primer not performing as designed.

For this reason, I will rotate the top rounds in a magazine with other rounds in the magazine (assuming that I am regularly chambering and ejecting ammo from those magazines without firing it).
 
Today 11:58 AM
pgdion A little quick research. Springs degrade in 2 ways.

Fatigue which is the result of cycling and is usually after 10's of 1000's of cycles. I don't think this is an area of concern for a magazine (more like for valve springs in a car).

And creep/relaxation which occurs from being under continuous load or compression. The amount of relaxation (as applies here) is a function of the load, temperature (not really valid unless your the guy that hides his ammo in the oven ;-) ), and time. So I would think storing a fully loaded clip over a long time would relax the spring. As the load on the spring as it compress is exponential, those last couple of rounds in the magazine will stress the spring the most. 8 to 10 in a 13rd clip would sound like a good choice. I'm happy with my 10 of 15 choice.

Some spring info here: http://www.lesjoforsab.com/technical...durability.asp

Incidentally, reducing the rounds would be less stress on deforming the ammo as well. Good point.
__________________________________________
Engineer, Scout Leader, Motor head, Shooting sports enthusiast
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Pgdion,
That was an informative read. Thanks for posting it!
 
I have read several articles and all the "experts" say that worrying about worn out springs is a waste of time. Personally I have 2 autos that I leave loaded all the time to max capacity and have never had a problem.
But my guess is if you are the type of person to worry about it, you are probably also the type of person to be at the range often enough to notice a problem before it becomes an issue.
 
I like to about twice a week... I know everyone says its not necessary...but...it cant hurt either...I dont think.
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You're putting excessive cycles on your spring, and getting more wear on the mag than if you'd just leave it alone.
 
So much nonsense and bad science in this thread. Comparing magazine springs to valve springs? Good lord.

Load your mags, keep 'em full, use them frequently. The springs will be fine, I promise. Cartridge deformation? You've got to be kidding me.

There are a dozen threads of people continually discussing this same topic. Does anybody use the search function?
 
Rotate only when smell and mold become evident. Other wise let things be as they are. Compressing and decompressing the magazine spring is what will cause a spring to wear out/fatigue.
Springs will not go bad from being compressed and the ammo will not go bad if kept in the magazine.

So much nonsense and bad science in this thread
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It must be true I read it on the internet and the TFL!:rolleyes:
How true your quote:cool:
 
Didn't see any mag springs compared to valve springs. I see lots of claims that the springs where out from compression / decompression. This failure mode for a spring, called fatigue, is not likely to occur in a magazine spring with it's very slow rate of compression and decompression and, even under heavy use, a very small number of cycles compared to what a spring is designed for. I would guess the shock from firing is harder on the spring than the cycling itself is. The valve spring was mentioned as an example of where spring fatigue is of great concern, where a spring may be fully cycled over 50 times a second and a cycle may take a few milli-seconds. It's used as a differentiator, not a comparison ... an example of why I don't think spring fatigue from cycling should greatly affect a magazine spring. What I have seen first hand with most magazines is how hard it is to get that last round in when they're new. They loosen up over time and I believe it is from the heavy spring compression each time you push in the last couple of rounds, each time it relaxes the spring a little more. I believe if you want your springs to last the longest, don't load the last couple of rounds and leave them there.
 
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Personally, I treat my magazines like any other machine - as parts that are going to wear out one day. I would like to tell you that I just use them and replace them when they are no longer working as desired.

In actual practice, I have a big pile of magazines (AR mostly; but a few others) that are no longer reliable that I keep around and try to fix. Left over habits from the ban era when that was a worthwhile approach. Considering what it costs to by quality components to rebuild a magazine (assuming the actual mag body isn't the problem), you are almost always better off trashing the non-working magazine and buying a quality new magazine.

Not to mention you avoid the irritation of the bad magazines working their way back into your "good" magazine pile. I swear those little bastards grow legs and sneak across the room at night.
 
..if you want your springs to last the longest, don't load the last couple of rounds and leave them there.
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My concern is for me lasting the longest. Never had a spring failure in 10s of 1000s of rounds, in magazines that are always fully loaded. YMMV.
 
Not to mention you avoid the irritation of the bad magazines working their way back into your "good" magazine pile.
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I put them out in the garage on a shelf. I should throw them out, but I too am still a little reluctant due to the ban.
 
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