Leave magazines full? School me...

[Superman]

I've used the interwebs to look up about whether you could harm your magazines by leaving them full all the time. From what I've found, they says the springs stay working just fine by not unloading them and it's just fine to leave them full all the time. I was just wondering what the consensus was here. Do you unload your magazines every evening and load them back up in the morning, or leave them full until they are fired out? Is there an amount of time that passes when you would unload to give the springs a "break"?

[Superman]

BTW, I leave mine next to the bed loaded. I have one full magazine of personal defense rounds in it and haven't unloaded the clip in at least a year. When I start to carry every day (hopefully starting Tuesday, depends on how nice the mailman is to me on Monday), I wasn't planning on unloading the magazines every night, but wanted to make sure I wasn't doing anything that would make my gun go "click" when I was needing a "bang"

[DocV]

Purely anecdotal but I left some magazines loaded for 20 years. They worked flawlessly.

[apostate]

It's not something I worry about with decent quality magazines. The 3 for $10 gunshow specials are another story, but I only use those for range guns.

[G.A. Heath]

Constant use, or loading/unloading, of magazines will wear the springs out. The springs are made of metal and metal fatigues with use so lets go to a real world example, paper clips. Take two paper clips set and then one down and leave it alone, take the other and bend one turn of it straight and then back into shape ten times. Then tell me which paper clip remains intact.

The problem with loaded magazines is not the springs, but rather the feed lips. Constant tension on the feed lips can distort them, however there are two ways to avoid that with most magazines. Keep the loaded magazine in the firearm or in a hard (metal or polymer) carrier that puts pressure on the first round and that problem is cured as well. PMAGS have that nifty dust cover which protects the feed lips as well, although there is speculation that their feed lips would not be damaged by prolonged pressure.

[Thomas]

No, you will not noticeably damage your spring by leaving the magazine loaded.

This is basically a "materials" question, and you will not be able to compress the spring beyond its limit of elasticity while in the magazine with just bullets. Since it doesn't enter that region of the stress-strain curve, the process will remain reversible.

[Jumping Frog]

You need to understand the underlying engineering principles involved with spring design.

In general, metals have an elastic range where applying a force causes the metal to deflect and removing the force allows the metal to return to its previous position.

If the force causes metal deflection beyond the elastic range, then there is permanent deformation in the metal -- the metal does not return to its previous position when the force is removed.

You can see this principle clearly with an ordinary wire coat hanger -- like the kind they use in the dry cleaners. If you hold each corner and apply force to bend the coat hanger about a half inch, it springs back when you remove the force. Now, apply force to bend the coat hanger to make a big U shape so the two corners touch each other. When you let go, the coat hanger is now permanently deformed and will stay in the bent position. You exceeded its elastic limits. If you bend a piece of wire back and forth a number of times, you will eventually break it.

Well, springs are engineered so that the designed range of spring movement stays within the elastic range. Properly engineered springs in some applications (car springs for example) are designed to withstand millions of compression-release cycles. Ultimately, what wears a spring out is when it exceeds the designed limit for the number of compression-release cycles.

That is why leaving a magazine loaded does not hurt the springs, because the spring compression is within its elastic range design limits. But constantly loading and unloading a magazine applies compression-release cycles that do eventually wear the spring out.

[carlson1]

I leave my loaded. I have never had a problem. I figured an unloaded magazine is like an unloaded gun.

[jimlongley]

Before my knee went, shot IDPA at least once a week and cycled my carry mags right along with all my others. It's been more than 4 years since my last IDPA, and a couple of weeks ago I took some friends shooting. No noticeable problems with either the bedside gun's mags, or the car gun's mags, or my bride's gun's mags, or my BUG's mags. All cycled properly.

I have also shot up WWII era Garand clips that had been loaded for 25 years or more without any problems, and M1 Carbine clips and mags.

[speedsix]

You need to understand the underlying engineering principles involved with spring design.

In general, metals have an elastic range where applying a force causes the metal to deflect and removing the force allows the metal to return to its previous position.

If the force causes metal deflection beyond the elastic range, then there is permanent deformation in the metal -- the metal does not return to its previous position when the force is removed.

You can see this principle clearly with an ordinary wire coat hanger -- like the kind they use in the dry cleaners. If you hold each corner and apply force to bend the coat hanger about a half inch, it springs back when you remove the force. Now, apply force to bend the coat hanger to make a big U shape so the two corners touch each other. When you let go, the coat hanger is now permanently deformed and will stay in the bent position. You exceeded its elastic limits. If you bend a piece of wire back and forth a number of times, you will eventually break it.

Well, springs are engineered so that the designed range of spring movement stays within the elastic range. Properly engineered springs in some applications (car springs for example) are designed to withstand millions of compression-release cycles. Ultimately, what wears a spring out is when it exceeds the designed limit for the number of compression-release cycles.

That is why leaving a magazine loaded does not hurt the springs, because the spring compression is within its elastic range design limits. But constantly loading and unloading a magazine applies compression-release cycles that do eventually wear the spring out.

...take it from the Frog...he's got jumping, tension, and springing down pat...

[74novaman]

Yeah, its a non issue.

Do the springs under your car wear out if you don't put the car on a lift in the garage every night?

[speedsix]

...yes...

...one opinion I found... http://www.youtube.com/watch?v=Da0qazI2Zi0" onclick="window.open(this.href);return false;

[Jumping Frog]

I understand about the elastic limits. But I still have a question. Why do some of the small semi-automatics say to replace the recoil spring at regular intervals? Is it because the design is pushing the springs beyond their elastic limits (like a poor design), or poor quality springs?

Every spring has a design limit on the number of compression-release cycles. The small semi-autos do not have much slide mass, so the spring does a lot more work in controlling the action cycling. Each shot is a compression-release cycle. Changing the spring at regular intervals simply helps to assure reliability and to also ensure you don't damage your slide.

[C-dub]

I understand about the elastic limits. But I still have a question. Why do some of the small semi-automatics say to replace the recoil spring at regular intervals? Is it because the design is pushing the springs beyond their elastic limits (like a poor design), or poor quality springs?

It may be because those springs are so small or because they are assuming some regular use or both. Regular can mean many things depending on the amount of use. It could be yearly, every five years, or every two months.