As an engineer myself, I agree with your engineer friend. As a restorer of double guns and maker of springs, I can add this. I see many guns that have been sitting unused
and left cocked for decades. When I remove the parts, clean and then reassemble, the springs are just as good as when they were made over 100 years ago in most cases.
Also consider this, most people at the turn of the century didn't use their guns any where near as often as we do today, with clay shooting and all, I would wager most were all kept in the
cocked position, when put away.
An Engineer should not be making rash statements such as the sentences above that I highlighted in
Bold Red Type.
First, I don't see how you could be certain that these guns have been "left cocked for decades". They could well have been cocked by your customers just prior to bringing them to you. More importantly, you could not accurately state that the springs in guns that are over 100 years old when you disassemble and clean them are "just as good as when they were made over 100 years ago." You would have to know how much force it took to compress them when they were made, and also know the exact measurement of their uncompressed size versus that same dimension today. Anything else is mere opinion, and engineers should be dealing with measurable absolutes... not opinions.
I am well aware that the springs installed in guns are normally under partial compression. I am also aware that springs tend to fail when they are under full compression. They are also more likely to take a set when left under full compression for extended periods. Gunsmiths and gunmakers make and sell replacement springs simply because they fail due to breakage or becoming too weak to reliably function. Like most things, they are more likely to fail when subjected to maximum stress, not from being kept in a relaxed or semi-compressed state. It doesn't matter if we are dealing with coil springs, V springs, leaf springs, torsion springs, or springs in a Grandfather's clock.
A couple other things are worth mentioning, I think. We have all seen those very high quality Best Guns that are often housed in prestigious Makers' cases, complete with accessories such as turn-screws, oil bottles, cleaning rods, and snap caps. Now why would these fine and respected gunmakers include SNAP CAPS if it was advisable to simply store their guns in a cocked state? In addition, we are all familiar with percussion and centerfire hammerguns, flintlock fowlers, flintlock rifles, revolvers, lever action and single shot exposed hammer rifles. Virtually nobody stores or leaves these firearms in a cocked state.
And virtually nobody is anal enough to worry that lowering those hammers and cocks is going to diminish the life of their mainsprings.
