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Thread: Question about wearing out a magazine

  1. #1
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    I'm new here, so forgive me if this isn't the best place for this topic.

    I''ve had a Glock 23 for about 8 months now, and it sits in the closet most of the time. However, if I were to need it in a hurry, I would have to load the magazine which takes time I might not have.

    My question is: I want to start keeping a full magazine with it, however, I'm worried about that wearing out the spring on the magazine. Is this something to worry about?

    Let me know what you think.

  2. #2
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    Keeping the mag fully loaded 24/7will not affect the springs in your gun, but the constant loading and unloading of the mag will cause the springs to weaken over time.

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    Contrary to popular belief, keeping a spring under tension will not harm it. Cycling sprigs is what wears them out. Keep it loaded, it will be fine.

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    Contrary to popular belief, neither cycling a spring nor not cycling a spring will wear it out. Stressing it into plastic deformation will.

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    What do you mean about plastic deformation?

    I still don't think I understand...

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    The FBI issues G23's and they keep their mags loaded all the time. In other words, load up, you'll be fine.

  7. #7
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    Useless if not loaded. Keep it ready.

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    Aether wrote:
    What do you mean about plastic deformation?

    I still don't think I understand...
    When a spring is stretched or compressed beyond a certain point (yield point) they will lose a bit of tension. You can try it with a spring from a ball point pen. Take it out and stretch it about 1/8", it pops right back to its original size. Pull it out 1/2" and when it goes back it will be a little longer and therefore a little weaker. Really yank on it, and it will just stay there having lost all spring qualities.

    When springs go bad in a magazine its because the wrong spring was chosen for the purpose. I bought a Mossberg 20 gauge some years ago, and it came with a magazine plug to limit it to 5 rounds. As this was to be a home defense weapon, I took the plug out and loaded it up with 7 shells. Last time I unloaded it for cleaning, I noticed that that last shell just kind of falls out with almost no spring pressure because the spring was originally intended to compress the length of 5 shells. When I compressed it that extra few inches, it weakened it.

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    Daddyo wrote:
    Aether wrote:
    What do you mean about plastic deformation?

    I still don't think I understand...
    When a spring is stretched or compressed beyond a certain point (yield point) they will lose a bit of tension. You can try it with a spring from a ball point pen. Take it out and stretch it about 1/8", it pops right back to its original size. Pull it out 1/2" and when it goes back it will be a little longer and therefore a little weaker. Really yank on it, and it will just stay there having lost all spring qualities.

    When springs go bad in a magazine its because the wrong spring was chosen for the purpose. I bought a Mossberg 20 gauge some years ago, and it came with a magazine plug to limit it to 5 rounds. As this was to be a home defense weapon, I took the plug out and loaded it up with 7 shells. Last time I unloaded it for cleaning, I noticed that that last shell just kind of falls out with almost no spring pressure because the spring was originally intended to compress the length of 5 shells. When I compressed it that extra few inches, it weakened it.
    Right on! But the ultimate yield stress wasn't reduced, that is 'weakening'. The spring was plasticly deformed and may still produce the same force but over a different smaller range of elastic deformation.

    It ain't rocket science but is beyond gallus-snappers.

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    Plastic deformation is when a material deforms inelastically. Basically, if you stretch it and it stays stretched it's been plastially deformed. If you stretch it and it elastically recoils back to its original dimensions then it hasn't been plastically deformed.

    Doug Huffman wrote:
    Contrary to popular belief, neither cycling a spring nor not cycling a spring will wear it out. Stressing it into plastic deformation will.
    Theoretically that would be correct, but even under the yield strength some plastic deformation occurs in a spring through cycling. Perthe book Material Science for Engineers Sixth Edition by James Shackelford pg 280-281, a direct quotation, but[] indicates minor edit :


    Many structural applications involve cyclic rather than static loading, and a special problem arises. Fatigue is the general phenomenon of material failure after several cycles of loading to a stress level below the ultimate tensile stress. [...] The data indicate that while [a specific material]can withstand a stress of 800 MPa (T.S.) in a single loading (N=1), it fractures after 10,000 applications (N=104) of astress less than 600 MPa. The reason for this decay in strength is a subtle one [...] repeated stress applications can create localized plastic deformation at the metal surface, eventually manifesting as sharp discontinuities (extrusions and intrusions). These intrusions, once formed, continue to grow into cracks, reducing the load-carrying ability of the material and serving as stress concentrators.

    So theoretically, if you neveroverstretched/compressed the spring you would never see plastic deformation, but due tothe formation of cracks (often times at grain boundaries andflaws in the material,)and crackpropogation, repeated cycles within the range will lead to some plastic defomation. It will be very slow, and may takemanycycles before any noticeable difference, wheras if youexceeded its strength by overtstretching ityou would instantly compromise it.

    Springs used in magazines are designed to withstand a lot of cycles, so I wouldn't worry about it in your regular use of a magazine.


    Also see: http://en.wikipedia.org/wiki/Fatigue_limit --> Depending on what the spring is made out of (and I actually have very little understanding of the properties of magazine springs in particular), the cycles it may withstand may be much more than what you are likely to encounter.

    Leaving the magazine loaded will not cause any wear.


  11. #11
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    Ha... I saw the subject "wearing out a magazine" and I thought this was a thread on OC'ing spare ammo

  12. #12
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    Felid`Maximus wrote:
    Plastic deformation is when a material deforms inelastically. Basically, if you stretch it and it stays stretched it's been plastially deformed. If you stretch it and it elastically recoils back to its original dimensions then it hasn't been plastically deformed.

    Doug Huffman wrote:
    Contrary to popular belief, neither cycling a spring nor not cycling a spring will wear it out. Stressing it into plastic deformation will.
    Theoretically that would be correct, but even under the yield strength some plastic deformation occurs in a spring through cycling. Perthe book Material Science for Engineers Sixth Edition by James Shackelford pg 280-281, a direct quotation, but[] indicates minor edit :


    Many structural applications involve cyclic rather than static loading, and a special problem arises. Fatigue is the general phenomenon of material failure after several cycles of loading to a stress level below the ultimate tensile stress. [...] The data indicate that while [a specific material]can withstand a stress of 800 MPa (T.S.) in a single loading (N=1), it fractures after 10,000 applications (N=104) of astress less than 600 MPa. The reason for this decay in strength is a subtle one [...] repeated stress applications can create localized plastic deformation at the metal surface, eventually manifesting as sharp discontinuities (extrusions and intrusions). These intrusions, once formed, continue to grow into cracks, reducing the load-carrying ability of the material and serving as stress concentrators.

    So theoretically, if you neveroverstretched/compressed the spring you would never see plastic deformation, but due tothe formation of cracks (often times at grain boundaries andflaws in the material,)and crackpropogation, repeated cycles within the range will lead to some plastic defomation. It will be very slow, and may takemanycycles before any noticeable difference, wheras if youexceeded its strength by overtstretching ityou would instantly compromise it.

    Springs used in magazines are designed to withstand a lot of cycles, so I wouldn't worry about it in your regular use of a magazine.


    Also see: http://en.wikipedia.org/wiki/Fatigue_limit --> Depending on what the spring is made out of (and I actually have very little understanding of the properties of magazine springs in particular), the cycles it may withstand may be much more than what you are likely to encounter.

    Leaving the magazine loaded will not cause any wear.
    So if you wanted to simplify that statement, you could say that cycling it will wear it out, not leaving it loaded :P

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