so I have been thinking why not buy 50 (or even 100) 30rd Mags and filling them up and storing them in the safe for when SHTF. how would the springs hold up? I know certain high cap mags for hand guns it's recomended to load 2 less rounds in them for prolong periods. I was wondering what everyones thought on AR Mags was. I would probably just end end up shooting them all on a long weekend anyway but I was bored at the CNC today and it was just a random thought I had.

For USGI and USGI style mags I would load only twenty eight rounds. For Pmags, FUSIL mags, HK and HK type clones, loading to a full load is okay. CS springs handle being loaded longer better than the standard milspec stainless spring but the milspec spring will still work.

When I changed the followers in my mags to Magpul followers I put oil on a cut up t-shirt and slowly followed the spring from top to bottom to help prevent rust in the ones that have CS springs. The cloth was just damp with oil, not dripping.



TS


to the Armory!

Thanks TS, gotta love how fast replies happen here hmm now to find the best deals on more Mags

My pleasure to be of help. Bravo Company and Cope's have good deals on mags right now.



TS

Loading and unloading mags is what wears out the springs. You can load up a mag for years, it will still work.

Jim

USGI mostly OKay mfg in 15 months in Iraq, never had an issue with it in 40 different mags I loaded to full cap n stashed around the FOB, people claiming the mag spring will mess up after a long time that way led me to leave two at home that will stay until 2012, I'll let ya know then

I trust that yours worked for you. My experience sucked though so I err on the side of caution.




TS

I know a guy who has at least 100 1911 mags loaded constantly. I know they're not the same, but these are all old style 7 rounders and he said he randomly would take one out and fire it (not knowing exactly how long that particular one had been loaded of course) and he's never had a problem out of any of them. That's the only experience I have with long loaded periods, I haven't had my AR long enough to find out and my pistol mag's never stay loaded long.

You weaken a spring by ruining its temper. Heat is what ruins temper. You get heat in the metal when you actually extend or compress it. Once it cools nothing happens.

So it is the act of loading and unloading that ruins mag springs because that's when the springs move and generate heat. Not leaving them compressed or extended.

in a mag I wouldn't say heat, it's more the compression and decompression of the scales of the metal n weakenin the bonds between them, corrosion is a larger factor contributing to that breaking down of the bonds so like TS recommended lubing them helps some

It is heat, when you compress a spring it creates kinetic energy which creates heat. It's that heat which breaks down the bonds and allows the carbon molecules to float out of their iron bonds because the iron relaxes a bit when it heats up. If you were to compress the spring, heat it with a torch and then quench it, it would stay pretty much compressed. The reason springs work they way they do is tempering which is only a process of applying and removing heat to make the piece hold it's shape. If you were to take 3 magazines to the range and run through them with a buddy reloading every spent mag for a whole day, I'd bet those mag's would start double feeding or failing to feed by the end of that day.

loading a magazine to capacity and firing it all day long prolly wouldn't even increase the temperature on the springs by a degree, the scales on the other hand are slipping against and under one another pushing their bond away from the next surface, lubrication helps to keep corrosion from getting under the edges of the scales and taking root thereby opening up the scales further to one another, yes friction is happening and yes heat is happening but at such a low measure it's not actually changing the temper but removing material enough to affect it's elasticity versus the force put against it by the rounds. Something with a spring say the size of a coil over on an automobile and the weight placed on it yes it is generating enough heat to affect temper as well as the scales pressing apart one another.

A CS spring will take being loaded over long periods of time better than stainless. It only makes sense that a spring will wear out with use, compression and decompression, like any other mechanical device or material.



TS

This post has been edited by TigerStripe: November 8th 2009 7:23 PM

Yep. 28 rounds in USGI, as noted above, and 30 in the PMags, and you'll be GTG. Between AR, AK, and HK(91) mags, I have well over 200 loaded rifle mags laying about!