Replacing Handgun Springs

[Caboclo]

Conventional wisdom says to change the magazine in your daily carry piece every couple weeks, to give the mag spring a rest. How about the rest of the springs in the gun? In a SAO gun such as the Glock or XD, the firing pin spring in always compressed when loaded. Since my carry piece is always loaded, should I be replacing the springs every year or so? Or keep some extra springs and and cycle them through every couple weeks when I change the mag? Wouldn't be hard with a little practice.

[ninjaamt]

You will probably hear that it is a good idea to rest springs when possible and switch magazines often. I think on your Glock ( I have a G19gen4 ) you can relieve the striker pressure before inserting the mag., unless you need to have a round in the chamber.

[JohnKSa]

While springs can weaken from being left compressed, I wouldn't automatically assume that this is going to be a problem until you have further evidence to indicate that there is an issue with the particular gun in question.

If the gun is a carry gun/self-defense gun, you should practice with it and check it on a fairly regular basis to insure proper function. If you determine, during one of these checks/practice sessions that you need to replace a spring, then replace it. Then keep an eye on it, and if you have to replace it again, now you have a pretty good idea of what kind of a replacement interval you should assign for the spring in question.

[Dfariswheel]

An engineer will tell you that springs don't deteriorate from being left under tension.
What causes them to wear is repeated stressing and un-stressing the spring.
In other words, you do more damage loading and unloading the magazine then if you just leave it loaded.

Since action springs, even in designs like the Glock that are "semi-cocked" are not anywhere near the fully stressed limit, there is little to no wear of the spring.
People carry 1911 pistols fully cocked for many years, day in and day out with no spring wear.

[JohnKSa]

An engineer will tell you that springs don't deteriorate from being left under tension.

Not this engineer.

They certainly don't always weaken from being left under tension, but it is possible under the proper set of circumstances. In other words, it's just as much of an error to automatically assume that a spring left under tension will deteriorate or weaken as it is to assume that it won't. Either could be true, depending on a number of variables.

Since action springs, even in designs like the Glock that are "semi-cocked" are not anywhere near the fully stressed limit, there is little to no wear of the spring.

It would be very unlikely for a partially tensioned/compressed spring to weaken from being left in that state. Unless the spring is poor quality or defective, or the design is very poor, it generally takes being left fully compressed or "over-compressed" to cause a spring to weaken.

The only reason this is ever an issue is if the designer views springs as a disposable part. When the "wondernine" revolution was taking place, it seems that gun manufacturers were scrambling to be able to claim a win in the capacity race and some of them achieved their goal by sacrificing magazine spring life. It's not a commonly seen problem these days in quality designs.

I came up with a spring tester a couple of weeks ago, but I need one more part to complete it. When it's done, I'll start an experiment on weakening springs from compression and post the results when the experiment is finally done.

[James K]

I hope you can test recoil springs as well and provide some objective information. I see folks claiming that recoil springs have to be changed every ten minutes or 10 rounds whichever comes first . I suspect they work for the spring makers.

Jim

[Bill DeShivs]

Springs aren't alive, and they don't need to "rest."

[JohnKSa]

I hope you can test recoil springs as well and provide some objective information.

It should work on recoil springs.

In it's current form, once I finish it, here are the limits on what I can test with it.
Compression springs with the following parameters:

Spring inside diameter >= 0.2"
Spring outside diameter <= 2"
Uncompressed length <= 10"
Spring compression force <= 110lbs

Compression weight measurement accuracy is better than an ounce.

The inside diameter is a hard limit, the maximum compression weight and accuracy can't be easily changed. The other parameters can be fairly easily adjusted with some different adapters or different length stock for the spring guide. Once I get it working to my satisfaction, I'll explain how I built it. It's not a complicated setup and I think all the parts together will cost me about $40. That doesn't count a bench vise which is required for its operation.

[Dixie Gunsmithing]

I have a spring engineering manual that was published internally by Lockheed Aircraft, if I can dig it up, that had some thoughts on this. Of course, when they designed a spring, it was for long life, but I remember they had several service factors used to calculate them.

[Caboclo]

Thanks guys. I appreciate the input.

[JohnKSa]

Dixie Gunsmithing,

It's certainly possible to build a spring that will last nearly forever, even if left compressed. However, there are usually other considerations that prevent the designer from considering ONLY spring life, or any other single design parameter, for that matter.

For example, in a magazine spring, the spring tension can't be so high that it deforms the magazine feed lips or body, squashes the rounds, is so difficult to compress that the magazine can't be fully/easily loaded, or that it creates so much friction between the top round and the stripper rail on the slide that it prevents the slide from moving freely.

In addition, the spring needs to take up as little space as possible to maximize the magazine capacity for a given size.

And, of course, magazines can't be too expensive or buyers will complain, and that means that the components of the magazine can't be too expensive either.

All of those considerations are, at the top level, in direct opposition to the design goal of maximizing spring life. In other words, the magazine designer must balance all of his design goals, many of which conflict with other important design goals to find a workable design.

The magazine he ends up with will probably have somewhat lower spring life than he would have liked, be slightly harder to load than the shooters would have liked, hold a round or two less than the marketing department would have liked, cost a little more than manufacturing and sales would have liked, etc...

[Dixie Gunsmithing]

JohnKSa,

I've been there, as I used to design automated welding and positioning machinery, and we designed custom springs for a few applications. There are several factors involved in it, not only spring life, but a balance of everything. To me, spring design is one of the harder things to do in machinery design.

If I remember right, the Lockheed manual has a service factor list for different applications of each type spring. These would be light duty, or on towards heavy duty, according to how much work they had to do over an amount of time, similar to selecting the hardness spec for gear teeth. If I can dig that manual out, I'll see what types of service factors would be similar or equivalent to different gun springs; hammer, recoil, etc.

[ClydeFrog]

I've never heard of any major problems with keeping modern semi auto magazines fully loaded. If you want to ease up on the factory springs you can not load a round or 2, like for a 17rd 9x19mm only having 15 rounds.
Springs are able to function for years with regular use. I would replace the pistol springs every 3,000 to 5,000 rounds if you are shooting full power loads; .45acp 10mm etc.
Wolff Gunsprings is highly rated by most serious gun owners or armed professionals for after market parts.