Isn't this widely accepted as being erroneous? Rather, working the spring (loading and unloading) the magazine is what weakens the mag spring. You could load a brand new magazine and put it in a box. Come back ten years later, shoot through the mag, and the mag spring should be as good as any mag that's been loaded and unloaded just one time.
No.
Coil springs will degrade with use, but if they're used as they're intended to be used -- within their design limits -- they'll probably outlast the gun.
That's why you'll find 1911 mags that have been fully loaded for 60 years that work beautifully -- they were well within their design limits. The same springs in an 8-round 1911 mag may not last as long, if left fully loaded or used regularly, as a 7-round mag spring. (Note: it's the same spring in both mags.) In that second case, they're being pushed harder when working (by compressing the spring farther) and they're also doing more work. The same is true with hi-cap mags -- they're compressed farther, and they're lifting more weight with each full cycle. (Same number of cycles occur with a 10-round mag as an 18-round mag, don't forget, yet the spring in the larger capacity mag has done almost twice as much work with each mag cycle.)
The same can be said of RECOIL SPRINGS. Some will last far longer than the gun or owner, while others (like the Rohrbach recoil springs) are supposed to be replaced every 250 or so rounds. Kind of depends on their design and what the gun designer is asking the spring to do. And if they're being pushed to their limit with each cycle...
Hi-cap and sub-compact mag springs are asked to do more than other mag springs, and are pushed farther into their elastic design limits than other springs. The more often they're pushed close to their limit, the more quickly they'll degrade. Leaving the Hi-Cap and Sub-compact mags fully loaded will cause degradation over time, but depending on their design, it may be quick or very, very slow. (Designers seeking to maximize capacity have come to view some mag and recoil springs as renewable resources; they use up springs to give the gun more capacity or operating potential.)
We've had this discussion many times on
THE FIRING LINE, and a search there about
mag springs and
recoil springs will give you well-documented sources and citations, as well as comments by engineers who are familiar with the technology. It may have been discussed on this forum, as well.
For most guns, it probably won't matter.
Note: Tappet Springs in cars will cycle millions of time over the car's life and almost never have to be replaced -- they don't get compressed that much (into their elastic range), but do get compressed many, many times. If cycling alone wore out springs, tappet springs would die a lot more deaths than they do. Wolff Springs, in their FAQ area, recommends downloading a round or two for long-term storage
on some mags. With most 10-round 9mm mags in full-size guns or 7-round 1911 mags, it's a non issue. Except for my home defense gun and my carry weapon, which generally stays in the safe, all of my other mags are empty.
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