Magazines and spring behavior - a good technical study on the topic

[lazyengineer]

The topic of magazines and best break-in practice comes up. I saw this article posted and thought it quite interesting. They took 8 replicates of a spectrum of 5.56 AR15 magazines as well as various handgun magazines, and did a series of tests over about 9 months. With magazines left loaded, unloaded, cycled. etc. And post a very interesting data-dump. What I got out of it was that yes- there is a break-in period where magazine spring tension comes down a bit. But then it stabilizes, pragmatically forever, as far as mortals are concerned.

https://www.ammunitiontogo.com/lodge/mag...ess-tests/

https://static-cdn.ammunitiontogo.com/me...114203.pdf

I always thought cycling a magazine spring helped break it in faster, but in the second link (the data-dump), they basically took half the mags and shot them every week, a good bit. And then left them loaded. And half the mags, loaded them, and didn't touch them again. At the end of the test period, both mags had about the same spring tension; both of which were a little lower than brand new.

They then hooked up to a machine and cycled the spring to failure. It took 70,000 cycles (of a 30 round magazine spring), to make one fail.

Another conclusion was that leaving a mag loaded didn't really hurt it. And leaving a mag only partially loaded, had no preservation benefit.


Anyway, gor the technical minded; it was a neat summary and some pretty neat testing.

[sundowner]

Thanks for the info and link .

[montana]

In the Colt armorers class we learned this about magazines:

One problem with plastic magazines such as MagPul is they are hygroscopic.

The only plastic magazine that is not hygroscopic is the Tango down.

The black polymer in the Magpul magazine is stronger than the polymers using the other colors..

[LRRPF52]

Biggest thing NOT to do is stretch your springs out “to give ‘em more power”.

That ruins the heat-treated shape and position and weakens them.

[Harpoon1]

I’ve always been told by many who should know, it’s the number of cycles that kills the spring tension/life, not the duration of compression. Seems counter-intuitive to some but, that’s been my experience. Albeit limited as it is!