An Experiment: Does leaving magazines loaded hurt the spring?

[mcb]

Hope you guys don't mind a link to my personal website. I did a simple experiment with two magazine springs and thought you guys might be interested in the results. Rather than posting all the pictures and text here I just added a new page to my website.

http://mcb-homis.com/magspring/index.htm

Feel free to post comments and criticism here. The experiment was pretty simply done and a lot more experimenting is need to say anything really important. At present it's simply a moderately interesting curiosity.

Thanks
mcb

[robinsre]

Good experimental design. Can you show that the amount of compression on your test spring is roughly the same as the amount of compression that would exist in a loaded magazine?

- Ryan

[deepdiver]

Great experiment. Well done and your conclusions for future experimentation were the same things I was thinking while reading through it.

[jeepinbanditrider]

When you magazine is full is the sping inside binding (the coils are touching) like they did on your test setup?

I know I still have a little "space" left when I load that 16th round in there and the spring is not completly compressed. When a spring binds (when all the coils touch each other) they loose strength over time.

Good work though. I would have to reconduct the test with the spring NOT fully compressed to see the results then. How tight was the locknut on top of the spring. Just tight enough to get the coils to touch or did you cinch it down a little.

[einheit 13]

No it doesn't hurt the spring. Either compressed or relaxed, the spring will be just fine. Actual 'use' is what weakens them. I have some 1906 Luger mags full of 7.65 that were still in the sealed ammo can. The ammo was funky but the mags still work just fine. 'Work' is what fatigues the springs, same as recoil springs, springs on your car, garage door, valve springs.......

Thats not the way to test the spring. They are not designed to 'bottom' out, look at how they compress-they will have an 'arch' to them. When you fully compress them and he 'ends' touch, you are actually re contouring/binding the spring and forcing it to take on a different shape. I have some Makarov mag springs that are progressive/conical that are desinged to be fully compressed. Good ideea, great presentation, wrong type of test....

[mcb]

Originally Posted by einheit 13

No it doesn't hurt the spring. Either compressed or relaxed, the spring will be just fine. Actual 'use' is what weakens them. I have some 1906 Luger mags full of 7.65 that were still in the sealed ammo can. The ammo was funky but the mags still work just fine. 'Work' is what fatigues the springs, same as recoil springs, springs on your car, garage door, valve springs.......

Thats not the way to test the spring. They are not designed to 'bottom' out, look at how they compress-they will have an 'arch' to them. When you fully compress them and he 'ends' touch, you are actually re contouring/binding the spring and forcing it to take on a different shape. I have some Makarov mag springs that are progressive/conical that are desinged to be fully compressed. Good ideea, great presentation, wrong type of test....

Actually most magazines fully loaded are very close to having the spring compressed to solid length. Try it, take the magazine base pad off and hold the magazine spring in with your thumb and load it up. The spring will be very close to being compressed to solid height. Not to mentions most properly design compression springs are designed to 'bottom out' as you say weather they are magazine springs, recoils springs or the springs in you washing machine. I suspect I would have gotten similar results even if I had not compress the spring to solid length but left not quite fully compressed with some space between coils.

None-the-less I never claimed this experiment proves anything thing conclusively but I certainly would like to do some more experiments given what I learned in this experiment. For what its worth I still leave several magazines for my CCW loaded full 24/7.

mcb

[robinsre]

The only other thing that would worry me is that your compression device seems to have allowed the spring to contort what appears to be about 30 degrees off center. In a well formed magazine the spring would compress directly on center.

I'm wondering if this could have any effect on the final length of the uncompressed spring at the end of testing.

- Ryan

Edit : another thing to consider is that magazine springs do not spend a majority of their life "uncompressed". Even just sitting in the magazine the springs are already compressed to what I would guess-timate would be 50% of their uncompressed size. Perhaps you should compare your resuts to a magazine spring that spent 14 months inside of an empty magazine....HEY there's an excuse to buy a new magazine right?!

[einheit 13]

Originally Posted by robinsre

The only other thing that would worry me is that your compression device seems to have allowed the spring to contort what appears to be about 30 degrees off center. In a well formed magazine the spring would compress directly on center.

I'm wondering if this could have any effect on the final length of the uncompressed spring at the end of testing.

- Ryan

It does have an effect, I should mentioned that. MCB, not trying to frost ya brother...I dwell in the world of 'second rate' and antique firearms that are the most crudist made weapons you've ever seen. I sometimes have to make my own parts or seek stuff from Europe through friends and family and importers that sometimes have literally been found in turned wheat fields or some of the old casemates from before WW1. I'm no gunsmith or machinist but through experience with 100+ year old springs and trial and error having to make stuff with less han jdeal tools and material, I can tell you with out a doubt that a half way decent mag spring doesn't care whether its compressed or relaxed......just like all steel products, actual 'work' is what 'strains' them. And if you stretch out the spring in your pic, I beat it'll work just fine. If not, stretchit and throw it in boiling water 15 minuts then immeiatly dunk it in ice water till it 100% cold. That'll give it a new memory, the 'poor mans' way......

[einheit 13]

Originally Posted by robinsre

Edit : another thing to consider is that magazine springs do not spend a majority of their life "uncompressed". Even just sitting in the magazine the springs are already compressed to what I would guess-timate would be 50% of their uncompressed size. Perhaps you should compare your resuts to a magazine spring that spent 14 months inside of an empty magazine....HEY there's an excuse to buy a new magazine right?!

want me to post you a pic of a 1975 issue AK74 mag spring that has never been installed vs a 1976 mag loaded with 7n ammo from E Germany straight from the tin of 50 loaded mags?? Still the same length, and from the same Russian plant.........But yes, always more mags!!!

[mcb]

robinsre I agree with both of your concerns If I was to doing the experiment again it would be with a larger sample of springs. I would also have some springs that were factory new never compressed at all and the rest would be put into magazines some empty some full.

einheit 13 no problem never thought you were frosting me. In my conclusion section of my article I propose that a new factory spring will take a set and loose some stiffness initial due to extended compression events, but I believe that the loss of stiffness is self limiting and would not result in any type of failure.

I really expected the spring that did not get compressed for an extend time to end up at the same OAL and stiffness after being cycled only a few times. I expected most of the initial set to occure due to initial compression. After 130 cycles it was still slightly longer and slightly stiffer than the spring that had only seen one extend compression cycle. This makes me wonder.

Its possible that another two or three hundred more cycles on the cycled spring and its properties would be the same as the extended compressed spring. It could also be as simple as manufacture difference in the springs they were identical spring but if one got better or worse heat treat due to some manufacturing problem?

As I said the result from this makes me want to do some more experiments. The result were just unusual enough to interest me.

mcb