Magazine Rotation.

[Thlax]

Side note-

Put a little piece of painters tape, duck, whatever and number them. That way you know which one your holding, and if you ever run into problems its easier to help identify if it's a mag problem.

 

[Ithaca37]

some magazine designs may be a bit aggressive on capacity, which means that the spring may experience some weakening over time.

Wrong.

Single stack magazines that are easy to load and contain high quality springs will probably not be affected by leaving them constantly loaded. Some double stack magazines (the ones that require you to use some sort of "loading device" to get the last couple of rounds in) are stressing the springs more and may take a set if left fully compressed over time.

Wrong.

Bear in mind that there cannot be one rule that will apply to every magazine spring out there.

Um, yes the rules are the same. All of you who have absolutely no idea what you are talking should refrain from commenting on the subject as you only confuse people and serve to perpetuate falsehoods with no basis in reality.

Proven science? Can you provide irrefutable scientific proof about every magazine ever manufactured? Or even one for that matter? To many variables, not enough constants. This myth will never be debunked entirely nor can it be proven to be true, if for no other reason than that there are literally thousands of different types of magazines manufactured over the years Out of many different grade metals and alloys. All of which have different behavioral characteristics.

You have no idea what you are talking. It is a myth and does not need debunking, just a simple lesson in materials. ALL steels do not experience creep at room temperature. Creep is the only possible failure mechanism that would occur under this kind of static loading. Scientific proof is sitting in every mechanics of materials book you pick up which is based on 100+ years of research and actual experience. Stop confusing people by pretending to know what you are talking about.

Assuming good quality springs that are matched to the application...yes. The problem is that not everybody uses good springs...your equipment being supplied by the lowest bidder and all.

All springs take a set when compressed or used. Properly engineered springs have had this set factored in.

The amount of plastic deformation that the spring will experience does not change with time under static loading. If a spring deforms plastically when loaded the amount of plastic strain does not change whether the mag is left loaded or unloaded immediately. This is simple mechanics of materials.

 

[danez71]

Wrong.

Wrong.


Um, yes the rules are the same. All of you who have absolutely no idea what you are talking should refrain from commenting on the subject as you only confuse people and serve to perpetuate falsehoods with no basis in reality.


You have no idea what you are talking. It is a myth and does not need debunking, just a simple lesson in materials. ALL steels do not experience creep at room temperature. Creep is the only possible failure mechanism that would occur under this kind of static loading. Scientific proof is sitting in every mechanics of materials book you pick up which is based on 100+ years of research and actual experience. Stop confusing people by pretending to know what you are talking about.


The amount of plastic deformation that the spring will experience does not change with time under static loading. If a spring deforms plastically when loaded the amount of plastic strain does not change whether the mag is left loaded or unloaded immediately. This is simple mechanics of materials.

Be careful of digging your heels in to the point of burying your head in the sand.

http://www.spring-makers-resource.net/spring-design.html
http://www.spring-makers-resource.net/compression-spring-design.html
http://www.spring-makers-resource.net/spring-designs.html
http://www.spring-makers-resource.net/support-files/materials_cross_reference_summary.pdf

If you take a gander.... be prepared to find evidence that doesnt agree with you.

 

[Drail]

I think he's already past that stage.

 

[Ben86]

While actual usage is what causes most of the wear on springs, compression does cause a little bit of fatigue. The only thing that cause no fatigue is when the spring is in its natural shape. Is it necessary to rotate? Not really, but I do it anyway to help insure reliability and spring life. It's just that important to me. I cycle my ammo and magazines every two weeks.

My rotation is more about putting fresh ammo in the mag, to keep from over exposing to moisture/over chambering ammo causing setback.

 

[nalioth]

I cycle my ammo and magazines every two weeks.

Then you should probably cycle your mag springs once a year, too.

 

[Ithaca37]

If you take a gander.... be prepared to find evidence that doesnt agree with you.

Ok, please enlighten me. I have looked through the material on those pages. I have seen it all before in basic engineering classes. Please quote the potions which disagree with what I have stated before because I do not see anything.

I think he's already past that stage.

Thanks for your wonderful contribution to this thread. Please tell me where and why I am wrong.

While actual usage is what causes most of the wear on springs, compression does cause a little bit of fatigue. The only thing that cause no fatigue is when the spring is in its natural shape.

Fatigue under static loading? How does that one work?


If you guys can show me where I am wrong I will gladly apologize and amend or remove any incorrect statements.

 

[danez71]

Ok, please enlighten me. I have looked through the material on those pages. I have seen it all before in basic engineering classes. Please quote the potions which disagree with what I have stated before because I do not see anything.

You also stated this.

It is a myth and does not need debunking, just a simple lesson in materials. ALL steels do not experience creep at room temperature. Creep is the only possible failure mechanism that would occur under this kind of static loading.

While "ALL steels do not experience creep at room temperature" some do.

Steel is an alloy. I'm sure you've learned in your basic engineering classes that various steel alloys, and how or if it is heat treated, will display various properties of elasticity, plasticity, and resiliance to name a few.

Here is some info on elasticity, plasticity, and resiliance.
http://en.wikipedia.org/wiki/Elasticity_(physics)
http://en.wikipedia.org/wiki/Plasticity_(physics)
http://en.wikipedia.org/wiki/Resilience


With out 1st hand knowledge of the spring and related mag's design, there is no way of knowing if 1) if it was even designed to be load, continously loaded, or left loaded to max capacity and 2) if it is actually capable of meeting the design.

I have looked through the material on those pages.

Please quote the potions which disagree with what I have stated before because I do not see anything.

I have no intentions of wasting the bandwidth needed to post the amount of info on those pages that pertains.

 

[1911Tuner]

This much I know. If I measure the free length of an action spring...install it...and leave it for a month, when I remove it and measure it again, it's about a half-coil shorter than it was originally, and it won't regain its lost length if left free overnight. If I shoot the pistol 2500 times...it's about three coils shorter.

 

[SSN Vet]

if you exceed the elastic limit of the metal, you will experience plastic deformation.

Unless you have detailed info. regarding the alloy and it's treatment (cold work, annealing, etc...) you don't really know the elastic limit. And unless you model up the spring and run a good FEA analysis, you don't know the amount of stress applied by loading the mag.

But Tuner's example shows measurable plastic deformation. Hence the elastic limit was exceeded somewhere.

My guess (and that's all it is) is that with the rectangular pattern springs typically used in pistol mags, you are getting some fairly complex stresses... not only bending in each straight of the spring run, but also torsional stresses at each corner. I'd bet a Snickers bar that the straights runs of wire are all still straight, but that the angle at each corner hasn't sprung back 100%. So a torsional elastic limit has been exceeded, and the spring has experience some plastic deformation and the stress-strain curve has shifted to the right.

And yes.. I think it's feasible that this could happen after one single loading and unloading cycle.

After the first couple load/unload cycles, the stress strain curve has probably shifted as much as it's going to and you'll be running along with a pretty stable geometry and spring force ever so slightly lower than had right out of the obx.

After 2,500 cycles, fatigue has surely ocurred. But I don't think the initial loss of length can be attributed to fatigue.

And my guess is that with normal spring steals, creap isn't happening at normal room temps.

Now donning flame suite in preperation for responses.

 

[Ithaca37]

While "ALL steels do not experience creep at room temperature" some do.

Now we are getting somewhere. Which alloys experience significant creep at room temperature? I am not familiar with any. I have only seen creep taken into consideration at high temperatures such as inside turbines.

Regardless of the answer to the above question, any alloys which may experience significant creep at room temperature would be excluded from magazine spring design or the effect of creep would be taken into account in the design. Either way, it becomes a non-issue. Furthermore, creep rates are generally very very low and would not really be an issue for how long magazine are left loaded even if it is months or years.

With out 1st hand knowledge of the spring and related mag's design, there is no way of knowing if 1) if it was even designed to be load, continously loaded, or left loaded to max capacity and 2) if it is actually capable of meeting the design.

This is all irrelevant. Saying that a spring may not have been designed correctly is not fair to the discussion. Of course a poorly designed spring will have problems.

BTW I checked all of those pages you linked to. No discussion of creep as a design issue. What was your point in posting those again?

 

[Ithaca37]

if you exceed the elastic limit of the metal, you will experience plastic deformation.

Unless you have detailed info. regarding the alloy and it's treatment (cold work, annealing, etc...) you don't really know the elastic limit. And unless you model up the spring and run a good FEA analysis, you don't know the amount of stress applied by loading the mag.

But Tuner's example shows measurable plastic deformation. Hence the elastic limit was exceeded somewhere.

My guess (and that's all it is) is that with the rectangular pattern springs typically used in pistol mags, you are getting some fairly complex stresses... not only bending in each straight of the spring run, but also torsional stresses at each corner. I'd bet a Snickers bar that the straights runs of wire are all still straight, but that the angle at each corner hasn't sprung back 100%. So a torsional elastic limit has been exceeded, and the spring has experience some plastic deformation and the stress-strain curve has shifted to the right.

And yes.. I think it's feasible that this could happen after one single loading and unloading cycle.

I stated this previously. This is simple physics. Equally simple is that the amount of plastic strain does not change under static loading (assuming no creep). This means that if a spring is deformed plastically when loaded it will not see additional plastic strain by being left under that static load.

Also, while I do not know which alloys are being used for magazine springs, nor what heat treatments they are being subjected to, you can be sure the engineers designing the springs have that data.

 

[danez71]

Now we are getting somewhere. Which alloys experience significant creep at room temperature? I am not familiar with any.

Regardless of the answer to the above question, any alloys which may experience significant creep at room temperature would be excluded from magazine spring design or the effect of creep would be taken into account in the design. Either way, it becomes a non-issue.

If its a non issue, why ask the question?

BTW I checked all of those pages you linked to. No discussion of creep as a design issue. What was your point in posting those again?

You brought up creep; not me.

You also stated this:

The amount of plastic deformation that the spring will experience does not change with time under static loading.

That is simply NOT true.

Taken from http://en.wikipedia.org/wiki/Creep_(deformation)
"The rate of deformation is a function of the material properties, exposure time, exposure temperature and the applied structural load."

"Unlike brittle fracture, creep deformation does not occur suddenly upon the application of stress. Instead, strain accumulates as a result of long-term stress. Creep is a "time-dependent" deformation."

"When subjected to constant stress, viscoelastic materials experience a time-dependent increase in strain. This phenomenon is known as viscoelastic creep."


You need to take a look at the viscoelastic properties of the particular steel alloy in use.
Taken from http://en.wikipedia.org/wiki/Viscoelasticity
"All materials exhibit some viscoelastic response. In common metals such as steel or aluminum, as well as in quartz, at room temperature and at small strain, the behavior does not deviate much from linear elasticity. Synthetic polymers, wood, and human tissue as well as metals at high temperature display significant viscoelastic effects. In some applications, even a small viscoelastic response can be significant. To be complete, an analysis or design involving such materials must incorporate their viscoelastic behavior. Knowledge of the viscoelastic response of a material is based on measurement"



You also stated this:

If you guys can show me where I am wrong I will gladly apologize and amend or remove any incorrect statements.

You have now been shown where you are wrong.

Possibly you havent reach that chapter in your "basic engineering classes".

 

[Ithaca37]

BTW I checked all of those pages you linked to. No discussion of creep as a design issue. What was your point in posting those again?

You brought up creep; not me.

Well, then what was I wrong about that those pages were going to set me straight on? You said that I stated something incorrectly in the post quoted below. Please tell me what is wrong in it that is contained in the pages you linked to.

Originally Posted by Ithaca37 View Post
Wrong.

Wrong.


Um, yes the rules are the same. All of you who have absolutely no idea what you are talking should refrain from commenting on the subject as you only confuse people and serve to perpetuate falsehoods with no basis in reality.


You have no idea what you are talking. It is a myth and does not need debunking, just a simple lesson in materials. ALL steels do not experience creep at room temperature. Creep is the only possible failure mechanism that would occur under this kind of static loading. Scientific proof is sitting in every mechanics of materials book you pick up which is based on 100+ years of research and actual experience. Stop confusing people by pretending to know what you are talking about.


The amount of plastic deformation that the spring will experience does not change with time under static loading. If a spring deforms plastically when loaded the amount of plastic strain does not change whether the mag is left loaded or unloaded immediately. This is simple mechanics of materials.

If its a non issue, why ask the question?

I like to learn things. Can you provide some examples of steel alloys that show significant creep at room temp or not? If there are some, I would like to know about it.

You also stated this:

Quote:
The amount of plastic deformation that the spring will experience does not change with time under static loading.

That is simply NOT true.

I also contend that creep is NOT a factor in spring design for room temperature applications. Therefore making my statement true. You can not cherry pick parts of what I stated.

You quote regarding viscoelasticity clearly agrees with me in that it says that for steels at room temperature under small strain, viscoelastic behavior is insignificant.

You have now been shown where you are wrong.

Possibly you havent reach that chapter in your "basic engineering classes".

I have not been proven wrong. You have misquoted me, ignored parts of what I stated to make sound wrong, and incorrectly tried to use a wikipedia quote to prove a false claim which the quote itself actually refutes.

All I care about at this point is some info on steel alloys which have creep problems at room temp.

 

[danez71]

Can you provide some examples of steel alloys that show significant creep at room temp or not?

I'll repeat to answer:
"All materials exhibit some viscoelastic response. In common metals such as steel or aluminum, as well as in quartz, at room temperature and at small strain, the behavior does not deviate much from linear elasticity. Synthetic polymers, wood, and human tissue as well as metals at high temperature display significant viscoelastic effects. In some applications, even a small viscoelastic response can be significant. To be complete, an analysis or design involving such materials must incorporate their viscoelastic behavior. Knowledge of the viscoelastic response of a material is based on measurement"

"All materials" includes all steel alloys. "Room temperature" means room temperature. It doesnt have to be a "significant" amount to make a difference. What part dont you understand?

I also contend that creep is NOT a factor in spring design for room temperature applications.

Please provide supporting evidence in this application.

You quote regarding viscoelasticity clearly agrees with me in that it says that for steels at room temperature under small strain, viscoelastic behavior is insignificant.

No it doesnt support you and it DOES NOT say that nor does it even use the word "insignificant" as you cleaverly inserted. It also CLEARLY SAYS (I'll repeat) " In some applications, even a small viscoelastic response can be significant. "

Please dont incorrectly re-word what I say or insert words that I did not say.

I like to learn things.

Please read the links and you might.

I have only seen creep taken into consideration at high temperatures such as inside turbines.

Just because you havnt seen it, it doesnt mean it isnt taken into consideration for other applications too.

All I care about at this point is some info on steel alloys which have creep problems at room temp.

If thats all you care about at this point, I suggest another forum.

ALL MATERIALS exhibit it. I can not possibly list ALL of the steel alloys in existance as the list is too long.


Its not a question of if there is creep. Its a question as to if the amount of creep has a negative impact.


Again, you stated:

If you guys can show me where I am wrong I will gladly apologize and amend or remove any incorrect statements.

You are incorrect that time does not play a part in creep.

You volunteered "apologize and amend or remove any incorrect statements".

Please do so.

 

[Kenneth]

Jeez! Ask a simple question!?. If jiminhobesound wanted to start a real peeing contest he would have started a thread about headspace. Down here on Earth most things in life are basically simple. The simple real world answer to the question is; no, you don't need to rotate your magazines. Fair or better quality magazine springs can remain compressed indefinitely. Like I wrote before, flexing the spring is what wears it. Even then, it would have to be flexed A LOT. If you practice once a week or more, use the same magazine, if the spring gets too soft you can (everybody brace yourselves) stretch it back out to nearly its original strength. Function check all of your magazines a couple of times a year just to be on the safe side.

significant viscoelastic effects. In some applications, even a small viscoelastic response can be significant. To be complete, an analysis or design involving such materials must incorporate their viscoelastic behavior. Knowledge of the viscoelastic response of a material is based on measurement"

What the @#&* does viscoelastic response of a material have to do with shootin’ the dang gun anyway?




"Our wrongs we must right if we can through the Ballot Box, and if this fails us, through the Cartridge Box."

U.S. Supreme Court Justice Joseph Story wrote;

 

[makarovnik]

I rotate mine every couple of weeks.

 

[danez71]

What the @#&* does viscoelastic response of a material have to do with shootin’ the dang gun anyway?

Not much if you dont consider the springs very important.

Fair or better quality magazine springs can remain compressed indefinitely

Hey.. cool... you just discover something that can release energy indefinitely.

You should bottle it, patent it, and sell it as the worlds next energy source for the indefinite future. We're finally free of oil!

Oh wait... I'm assuming you ment that not only can the be compressed indefinitely but also spring back too.

 

[Kenneth]

Hey.. cool... you just discover something that can release energy indefinitely.

“Yer a genius Gump”

Oh wait... I'm assuming you ment that not only can the be compressed indefinitely but also spring back too.

Yes, hence the name, “spring”. Otherwise it would be known as a “bend”.

You should bottle it, patent it, and sell it as the worlds next energy source for the indefinite future. We're finally free of oil!

I’ve dreamt of harnessing the energy used to compress springs in the first place all of my life. I’m just not sure if mankind is ready for it. After all, it is a force that can be used for evil as well as for good.

I didn’t spend all those years at Wossamotta U getting my Ph.D in Thinkology for nothing.

As a practical matter, static loading still wears a spring less than constant flexing. I keep all my magazines for my SHTF firearms full. I practice with one magazine for each gun, and I function check all of my magazines at least twice a year. I have never experienced a magazine spring related malfunction on any of my firearms.

Just as a side note danez71, if I was scoring, you would get more points than Ithaca37, however you could widen the margin by using the spell checker.



"Our wrongs we must right if we can through the Ballot Box, and if this fails us, through the Cartridge Box."

U.S. Supreme Court Justice Joseph Story wrote;

 

[Ben86]

I practice with one magazine for each gun, and I function check all of my magazines at least twice a year.

How do you practice reloading?

 

[danez71]

Yes, hence the name, “spring”. Otherwise it would be known as a “bend”.

LOL.... or maybe "flat wire".

Just as a side note danez71, if I was scoring, you would get more points than Ithaca37, however you could widen the margin by using the spell checker

Thats like free extra credit!
(I need to use that little free button more often than hardly ever)

 

[ForumSurfer]

Since I switched to 9mm, I'm practicing once or twice weekly...so I'm rotating my mags weekly from what I just realize. I have several mags, but I colored the glock emblem in on 3 of them and those are my carry ones that I clean regularly after dropping them in the dirt during practice sessions and drills.

 

[walking arsenal]

Forget the springs. I'm more worried about the feed lips bending out from being under all that pressure than I am the springs going.

What are the chances of magazine feed lips going south after extended periods of being loaded?

 

[ForumSurfer]

What are the chances of magazine feed lips going south after extended periods of being loaded?

Slim to none on a pistol magazine. Nearly nonexistent on a glock mag since the plastic reinforces the steel.

 

[nalioth]

What are the chances of magazine feed lips going south after extended periods of being loaded?

Slim to none on a pistol magazine. Nearly nonexistent on a glock mag since the plastic reinforces the steel.

To be perfectly honest, I've only ever seen AR15 mags afflicted with this issue.

I see posts that ascribe this to just about any other magazines, but have never actually seen it.