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Leaving Magazines Loaded

Discussion in 'Valuable Info' started by jonathon, Sep 10, 2005.

  1. Rocetmal


    Nov 14, 2007
    If I'm going to have a gun fight, I will take a brand new never loaded Glock, Sig, or Kimber mag over any mag in the world that has been left loaded to capacity for 25 years, or even one year. A guy I certified as an instructor a few years back who owns a security firm brought a CZ over the other day with feeding problems. The spring tension was almost non existent. I told him to get a new mag, he did, and no more problems. You may say its a myth perpetuated by spring makers, but I'd disagree - also I have a good friend who is a gunsmith. I don't know, sometimes facts are good to have, and sometimes real life experience plays a different hand, who knows eh?

    For reference, check out the FAQs:

    Also, it is good to cycle your bullets regularly. The reason I never send the same bullet home twice ever is that the kinetic energy expended when the slide slams forward to chamber the round is enough to weaken the crimp or potential pressure that bullet can contain significantly. A bullet puller is a hammer like tool that you put the bullet into when you've screwed it up seating the bullet too deeply, and you want to pop it out and reseat it. All you do is put the bullet in a bullet case holder inside a plastic container on the hammer like object, give it one swift swing down on a table and out pops the round. That's all it takes. So, every time you send a round home, you give it at least 20% of what a bullet puller puts on it in terms of kinetic energy that loosens the crimp.
  2. JohnKSa


    Sep 8, 2000
    DFW Area, TX
    Sounds like the springs "took a set". :supergrin: How could that possibly happen?

    I find it amusing that often the same people who claim springs don't weaken from being left compressed will tell people who complain about their mags being hard to load fully that they should load them up and leave them for awhile. Then they'll be easier to load. Hmmm... Let's think about that for a minute.

    Here's the truth about springs.

    Well designed springs, constructed from good quality materials and manufactured properly will not weaken appreciably from being left compressed. If you compromise any of the above qualifiers (design, materials, manufacture) then they can weaken from being left compressed. Furthermore, springs, even ideal springs, will weaken very slowly over time from being cycled, and they will also weaken significantly if they are "over-compressed".

    It's VERY rare to find a good quality single column magazine that has problems with being left fully loaded for two reasons. First of all, the spring bends tend to be very smooth (rounded) in typical single stacks while double-column mag springs often have corners and sharp bends (good design). Second, single column mags aren't usually designed with the goal of squeezing every last bit of capacity out of the gun (springs not over-compressed when fully loaded). The maker would have gone to a staggered design if that were a major design goal.

    Anyone who doesn't believe springs can be weakened from constant compression just needs to talk to an experienced spring-piston airgunner. Spring-piston airguns are powered by large springs. Since those springs are the heart of airguns that may cost several hundred dollars, they are very high quality springs. And yet, any spring-piston airgun manual will tell you not to leave the gun cocked (spring compressed) for any longer than you need to. They'll tell you that shooting the gun won't hurt it, but leaving it cocked will weaken the spring. For those who doubt, this "theory", it can be and has been tested. The results of one such experiment used to be posted online but the link is now defunct. However, if you're really interested (or hard to convince), you can probably find the "R1" book by Tom Gaylord. He includes the results of a similar test involving several premium springs from custom spring makers. Even these specially made springs showed easily measurable weakening from being left fully compressed.

    The problem with spring-piston airguns is this. The spring can't be so strong that it's impossible for the average user to cock it and yet it needs to produce maximum power for its size. The compromise that airgun designers accept is to overcompress the spring. That provides a great power to size ratio while still keeping cocking effort reasonable.

    Magazines are a similar compromise. Spring power can't be excessive or the ammunition will be damaged, the slide won't be able to strip rounds and the magazine will be impossible to load. But we still want to maximize capacity. Some gun makers decided that the way to achieve this is to overcompress the spring--it's no big deal, especially since springs are a low-cost maintenance item anyway. EXCEPT that many well-meaning but ill-informed people have spread the myth that springs don't ever weaken from being left compressed.

    So, what's the bottom line?

    Check your equipment regularly (we all do this anyway. Right?). If you note springs weakening from being left loaded, replace them with high-quality parts--first you want to eliminate the possibility of quality issues. If they weaken again from being left loaded, replace them again but now you've determined that even quality springs are going to weaken in your magazine design. You have two options at this point. You can either underload the mags by a round or two or determine how long the springs will last and simply replace them before they begin to weaken. Mag springs are cheap, even the best ones.

  3. I agree with all that was written about leaving mags loaded without any affect on the springs. I really believe this all to be true. It makes sense.
    BUT, I left two Colt .45 mags fully loaded for about 20 years. And guess what happened when I ran them through the gun? Yep...about 2 or 3 rounds from each mag were FTF. I then loaded up 3 other mags that were left empty for the same period of time and ran them through my Commander without any problems at all. All ammo was from the same batch. :faint:

    Any ideas?
  4. dp509


    Jul 20, 2007
    Several years ago, we had two officers on a domestic call where a grandfather beat his grandson. Officers arrive, grandson said that grandfather had a revolver in his truck. After officers arrived and spoke with grandson, grandfather exits residence and runs to his truck. Officers are too far away to grab him. He comes out with the revolver shooting. :wow:

    One officer is carrying a Sig P220. He had never let his magazines rest or swapped magazines every month (he only had three).

    The other officer is a carry a S & W .45 Long Colt 4" Nickel.

    The officer with the Sig got off one round. The magazine failed to feed the next round up. :faint: He missed with his one and only round fired. :embarassed:

    The second officer hit him with a .45 Long Colt in the chest. He was DRT :whistling:.

    The Sig was checked and it was found that all three magazine springs were worn out. They were replaced with wolf springs. The gun ran flawless after that. He also bought extra magazines and swapped them every month.

    The officer with the Sig later retired and the officer with the .45 Long Colt got promoted to SGT. :tongueout:
  5. JohnKSa


    Sep 8, 2000
    DFW Area, TX
  6. d3athp3nguin


    Aug 7, 2007
    I remember purging my dad's 15-year old hollow points downrange that had been sitting in mags for 15 years, and I experienced no problems whatsoever. I did take apart the mags and found that the spring on one was slightly rusted, so I cleaned it. The mags still work fine, though I still have that nagging urge to buy more mags for the gun because...well... age affects everything, and those mags have been sitting loaded for a looong time...

    I don't see how rotating mags and cycling ammo, say, every year would hurt. I think it is a sensible middle ground for people who are unsure about which side of this debate is "right." From either way you look at it, you are leveling out the "wear" on your mags. If you rotate your range and carry mags every year, you are either giving the range mags a break by leaving them compressed, or you are giving the carry mags a break by having them loaded less often for a year. Then you can also shoot your carry ammo out before rotating, and satisfy any paranoia about your carry ammo going bad.

    Then buy two new carry mags whenever you've convinced yourself that none of your mags are reliable for carry anymore.

    Problem solved!
  7. dwebb210

    dwebb210 NRA life member CLM

    Jul 26, 2004
    I know it has been a while since anything has been added to this thread,
    but after seeing this I thought it deserved a comment.

    Any surface defect in a spring can serve as a place to initiate a crack.

    While light surface rust may not be enough, "corrosion stress cracking"
    is a real metallurgical issue and should be considered when talking about
    a firearm magazine.

    I wouldn't think twice about keeping the magazine for range use only,
    but if it was a magazine I wanted to actually rely on, I would replace the
    spring as the rust has caused at least some pitting, and increased the
    likelihood of the spring to break.

    On a tangent, I will add that at one time I owned of of those Scherer 33 round
    magazines made for a Glock 9mm. I filled it with ammo, but never used it
    in a gun. A year later I took the ammo out of that magazine, and the
    spring had lost so much of it's shape that it failed to bring the last 5 rounds
    to the feed lips. As stated before, there are good springs, and bad springs.
    Scherer obviously doesn't know how to make good springs.
  8. SW342

    SW342 *****

    May 12, 2007
    The Republic Of Texas
    I have always left my mags loaded, but not saying that is the proper thing to do....just something I have always done.


    Jul 16, 2008
    JBLM, WA
  10. TangoFoxtrot

    TangoFoxtrot OIF 04-05

    Sep 10, 2008
    Nowhereville, USA
  11. Dogguy


    Aug 2, 2008
    Soggy South.
    Very interesting thread.

    But I would like to point out that the reason you hear about magazines being left loaded for decades and still being able to work perfectly is because it is an unusual event. I would venture to guess that the vast majority of magazines left loaded and unattended for extended periods of time do cease to function properly. Personally, I have four first generation, NFML G19 mags that are all due for new springs. They've been rotated regularly but they're almost 20 years old and they simply are getting baggy and saggy with age (kinda like I am :whistling:).

    All springs eventually will eventually lose elasticity over time when compressed. Compare some older magazine springs and recoil springs with new ones. They flatten out a bit and don't return to their original length. I'm not a metallurgist, physicist or scientist in any respect but I do have pretty good powers of observation. And my observation is that any spring will lose some of its "spring" if you keep it compressed long enough. If I'm depending on the cartridges in that magazine to keep me alive, I'd prefer the spring to still be springy.

    It will happen to your automobile springs as well, given the time and circumstances. I can remember once having a co-worker who was very obese--she probably weighed in a little over 400 pounds. She drove an old Toyota Tercel (IIRC). That little car was permanently tilted toward the driver's side, even when she wasn't sitting behind the wheel. A fine example of over compression.

    Everyone has an opinion. It appears to me that those who depend on self loaders to keep them alive usually recommend some scheduled decompression of magazine springs and periodic replacement of recoil springs. It seems like common sense to me, despite what the magazine article quoted in the opening thread had to say.

    But, of course, common sense is relatively uncommon these days.
  12. I'm no expert, but from what I've been told is that springs wear out because of use, not from being constantly compressed at the same length. My first thought was that it does wear out the springs, but the experts beg to differ, so I'll defer to their judgement.
  13. Glockdude1

    Glockdude1 Federal Member CLM

    May 24, 2000
    I leave my mags loaded. Never had a problem.

  14. PBR Sailor

    PBR Sailor

    Dec 4, 2004
    Local PD here with 200+ officers carrying Glocks. Some officers were adamant that the magazines could be loaded forever without any problems. because a Glock rep told them so. Time passed by and there have been several instances where the slide would not lock to the rear after the last shot with an old magazine. The pistol worked fine otherwise. New magazines fixed the problem. A friend of mine with the PD unloads his magazines completely once per month then loads them right back up. He's been doing that for several years with no more problems.
  15. mikeJ


    Jan 8, 2008
    :wow: You can't use them if they are not loaded!!!!
  16. Glockdude1

    Glockdude1 Federal Member CLM

    May 24, 2000
    Still sounds good to me, the magazine fed every rd. My AK or my Uzi bolt does not lock back when the magazine is empty. No problem for me.

  17. DoubleTapFL


    Dec 28, 2008
    great article, thanks for the info
  18. gunderwood


    Jan 9, 2009
    I decided to look at custom/high performance spring manufactures (not gun springs). I wanted to look for a generic, engineering answer and I found one.

    In short, the engineering community agrees that springs do not have issues with storage in a none rest state as long as the are operated in a range of compression or elongation that does not deform the spring. Instead the consensus was that springs wear out through cycles. Thus, your mag springs get softer or wear out by loading/unloading the mags.

    Storing any number of rounds in a mag (0-max) has no impact on spring performance or lifespan since you do not deform the spring (if you did it wouldn't work after the first load/unload cycle). However, changing the follower to cram another round or two into a mag might compress it enough to slightly deform it.
  19. JohnKSa


    Sep 8, 2000
    DFW Area, TX
    That's the major key that is usually left out of these discussions.
    Unfortunately the first part of this statement is not universally true (though it is usually true) and the parenthetical is just plain false.

    It is true that the designer will USUALLY make sure that the springs are not overcompressed, HOWEVER, there have been magazine designs, especially early in the "wondernine" era that overcompressed the magazine springs when fully loaded.

    NO, they will NOT automatically fail immediately, but it does shorten the life of the spring, and it gets worse the longer it's left overcompressed. I made a post back in May of 2008 that contains a link to a test demonstrating that it's possible to overcompress a spring without causing immediate failure. Furthermore, a post made on this thread in April of 2008 gave an example of pistol magazine springs weakening from being left fully loaded for a long period. It CAN happen although it's generally not an issue.

    Proper materials & manufacturing process are also important, but are mostly not an issue with quality products.
    Last edited: Jan 11, 2009
  20. gunderwood


    Jan 9, 2009
    The whole post is dependent on the first paragraph. A good design does not operate the springs in any manor that deforms them. Certainly some manufacturers have made mags that do deform the springs.

    We have to be careful here and define failure. All the spring manufacturers that I contacted (internet/engineering papers, email, phone) defined failure as a modified spring. If you over-compress the spring you have changed the properties of that spring. To them, with their extremely expensive equipment (spring testing machines), a spring that changes its properties (and wasn't designed too) has failed. It may still work in the application for a period of time, but is unlikely to have the lifespan or performance they designed it to have.

    A simple test of gun functioning or not is not sufficient for me. I wanted to know what the engineering and physics behind springs were. The real way to test this is to take several brand new mags and remove the springs. Test them on a spring calibration machine. Then load them up and store them for a period of time and then retest. While your at it might as well have a good engineer who designs springs for a living, look at the design.

    I'd love to do this, but I'm only short a calibration machine. The problem with a gun test is you can not easily eliminate all the other variables. Also, you are unlikely to have sufficient sample space to get statistical results. A gun/shooting test should also be double blind.