[JohnKSa]

The springs I make are leaf springs, for the most part.

This test is exclusively applicable to coil springs.

What I'm saying is that it SHOULDN'T happen.

Everything in design is a tradeoff. If you are trying for maximum capacity and minimum size then, as a designer, you may be willing to give a little in other areas--like depth of coil spring compression. It's a common tradeoff in the spring-piston airgun world and with well-known effects. More on that later.

Whether the springs are designed that way is irrelevant. The manufacturer knows the springs will be over stressed and recognizes it. I'd call that sacrificial. Whether it's "improper design" is up to the individual's interpretation.

I think there are a lot of misconceptions about springs in the firearm world. Why that is, I don't know.

What I do know is that springs can weaken from being left compressed if they are compressed deeply enough. At about 50% compression, a spring will pretty much last forever assuming it's decent quality and made with some reasonable level of care. As the compression level increases past 50%, the longevity of the spring depends more and more heavily on the quality of the materials, the design of the spring and the quality control. As the compression level approaches 100%, it becomes a matter of fact that the spring is going to weaken to at least some level if it's left compressed for long periods--no matter how good the materials used, regardless of how well it's manufactured or how good the QC is.

Why this isn't accepted in the firearm world is a mystery to me. It's common knowledge in other fields.

http://www.airgunsofarizona.com/blog...ro-piston.html

“When you are using a mechanical spring in an airgun, you are just doing bad things to the spring,” Schultz adds. “A rule of thumb in engineering is that you don’t want to stress a spring past 50% compression to maintain reliability, but that doesn’t work in a spring gun. Instead, you compress the spring almost 100%. You take up almost all the gap between the spring coils to get ultimate performance, and that tends to weaken the spring. And if you leave it cocked, you’re taking some life out of the spring. So you use special materials and do special heat treatments to deal with that, but you’re basically fighting a losing battle.”

Magazines are a similar application in that they tend to compress the spring to, or nearly to, 100% compression.

At any rate, it seems moot. The test shows that leaving magazines fully loaded can weaken the springs. The weakening was noted in both magazines although it was much more pronounced in the Ruger mag than the Glock mag. At this point--given that I haven't range tested either spring-it's entirely possible that the weakening hasn't progressed to the point that it will cause failures, but that's another issue. Clearly leaving the springs compressed did weaken them.

That may surprise some folks in the firearm world, but it's not news to everyone. There are a couple of well-documented tests in the spring-piston airgun world that demonstrated that leaving metal spring-piston airguns cocked results in a weakening of the springs. In those two tests, every spring tested showed some weakening, and the weakening tended to increase the longer the springs were left compressed. It was true even in the case of top-quality custom replacement springs.

I wonder if this is just one of those things that we over worry and over obsess about.

Those who are are missing the point. This isn't something to worry or obsess about, but it is something to be aware of.

We don't need to worry or obsess about tetanus, but we do need to be aware of it and how to deal with it constructively by taking preventive action.

In both examples, springs and tetanus, knowing that the problem does rear its head from time to time is actually quite valuable. It's only when we pretend that it's a non-issue--that it never happens--that we can get into trouble.