Bill DeShivs said:
Remember- Wolff SELLS springs.
It wouldn't do them much good to tell you that springs generally don't wear out. Instead, they tell you that changing them is a good practice to prevent problems.
Read between the lines- and take it with a grain of salt.
Same old routine, Bill? You always revert to form when the subject of springs comes up -- and you always slam Wolff Springs. (Never say anything bad about other firms, like ISMI, who also sell springs.) If factory mag springs are so great why do people ever need to buy replacement springs? And why do firms like Wilson use Wolff springs as their OEM springs for their custom guns? You seem to be saying the people just buy springs because they've been sold a bill of goods and buy they for no reason? They don't really need them, or they're foolish enough to buy guns with crappy springs.
In their FAQ area, Wolff Springs tells folks to download hi-cap mags a round or two when they've being stored for long periods -- as downloading them will extend spring life. Wolff talks about a spring's
elastic limit -- and how, if you go beyond that limit, the spring material can degrade.
If Wolff's intent is to sell more springs, seems as though they just say "load'em up and store them." That's NOT what they do. They're actually selling fewer springs than they could. We've had a bunch of long discussions on this topic here, and some of the folks who participated are engineers very familiar with the topic. At least one metallurgist took part in these discussions.
JohnKSa, a member of TFL staff, did some long term tests here a while back, and you were involved in discussions about those tests. Here's a link:
https://thefiringline.com/forums/showthread.php?p=6005156#post6005156 His tests showed real-world degradation that happened relatively quickly... but he also noted that the mags continue to work. (I don't know if he continued the tests beyond the last data shown in the link.)
New springs WILL take an immediate set when first put to work. Spring designers know this. Buy a new Glock mag and you'll experience it first hand, when you feel you need a hydraulic press to load the last few rounds in a Glock 17 mag. It gets better over time, as the springs lose a bit of their resistance.
Springs ALSO degrade if they are pushed to or beyond their elastic limits. Cycling a spring won't always or necessarily wear a spring out -- unless, when the spring is cycled, it's compressed too deeply.
Some mag designs prevent that, others use extra-deep compression to provide extra capacity.
On the other hand, if you have some 17-(or higher) round high-cap mags and never load more than 15-rounds in them, those springs might last as long as 7-round 1911 mag springs. But if you keep those mags fully loaded while carrying or storing them, you MIGHT see some failures sooner than you'd expect. It'll will depend on the spring and mag design, and all mags are not designed to perform in the same way.
SIGSHR said:
I recall Jeff Cooper writing that he saw a 38 Super magazine that had been loaded in 1929 work fine after over fifty years. Conversely W. E. Fairbairn recommended firing duty magazines every three months.
Jeff Cooper and W.E. Fairbairn probably weren't much into hi-cap mags, and double-stack (hi-cap) .45 were NOT really all that common until Faribairn was dead and Cooper was much less active as a shooter or instructor.
Competitors, who make their living with their guns probably will likely change springs more often -- having learned the downside of not doing so. (A lot of them probably changed springs without needing to, but they viewed it as cheap insurance.)
Magazine spring life didn't become a big concern until hi-capacity mags became available and popular. Most mags for older guns were designed so that the springs were NOT compressed all that far. The original 1911 mag was designed to hold 7 rounds, and those mag springs would last for decades when left fully loaded. But when the first 8-round mags for 1911s didn't perform as intended -- the mags failed far more quickly and frequently than expected.