Stretching Mag Springs?

[JohnKSa]

You shouldn't need to replace the mags. Replace the springs and you should be good to go. It probably wouldn't hurt to replace the followers too.

It takes a lot of use to wear out the spring in a real 7 shot 1911 magazine.
But when they pushed them to 8, something had to give and the spring was it. When shooting exclusively IDPA CDP, I had to replace Wilson springs about every other season. Some high volume shooters changed them every year.

Correct. Assuming good quality springs, the most likely cause of early "death" is overcompression.

It's true that springs will gradually wear out from being cycled, but if they are overcompressed then they will wear out much faster.

Some magazine designs apparently overcompress the springs enough to cause reduced spring life, especially if the magazines are left loaded. It's not common but it does happen.

As I mentioned earlier, this sort of thing is a non-issue in the mind of some European gun designers. They are designing guns that intended to be serviced regularly by an armorer. The normal wear parts, including some springs will be replaced during normal inspection/maintenance before they start failing. The fact that a $2 spring that will be replaced annually would likely fail after 2 or 3 years if it weren't replaced is a good tradeoff for being able to stuff an additional 1 or 2 rounds into the magazine without making the gun bulkier.

It only becomes a problem if the gun falls into the hands of someone who believes or is told that springs don't wear out.

 

[HotShot.444]

It's all "steel" .... or is it?

Automotive coil-spring valve-trains have lasted to well over 500,000 miles. That is a LOT of cycles. While they seldom experience great "extension" moments, still they are nearly always under compression and flex. Does this analogy hold true for magazine-springs? Seems to be, if your springs' molecular composition is damaged by mere use, and the structure of the spring becomes unsound, then you bought the wrong brand of gun. Are all brands' magazine springs exhibiting this same problem? How about non-stock replacement magazines by some of the popular makers; do they lose "set" also? .444

 

[madmag]

if your springs' molecular composition is damaged by mere use,

Yes, all (steel) springs are damaged by use. The flexing causes internal friction that finally weakens the spring.

How about non-stock replacement magazines by some of the popular makers; do they lose "set" also?

Yes.

 

[JohnKSa]

Automotive coil-spring valve-trains have lasted to well over 500,000 miles.

Try to compress a valve-train spring with your thumb enough to make space for 15 rounds and you'll gain an appreciation for why magazine springs aren't quite as robust as valve-train springs.

It is certainly possible to make magazine springs that would last forever. The problem is that you either have to limit the capacity to insure that the springs are never compressed much or you have to make them so robust that they would be impossible to load without some sort of special tool.

Magazine springs are the result of several design tradeoffs. A few of the more obvious ones are listed below.

1. They have to have a compression length that is suitable for an appropriate number of rounds.
2. They can't be too stiff or they will be too hard to load and may damage the rounds.
3. They must provide a reasonable service life.

If, as a gun designer, you value capacity very highly and consider springs to be normal wear items then you might trade off a little of 3 for an improvement in 1.

If you value durability highly you might trade off a little of 1 for a lot of 3.

If you value money you won't trade off 2 for anything.

 

[Amin Parker]

I have been stretching springs for years with great success. Buying a new magazine is obviously the best option but stretching it does work

 

[Walt Sherrill]

JohnKSa's comments match exactly the points made by Wolff Springs in their Frequently Asked Question area. He makes a point that I've made here, frequently, too -- many of the new guns, including some very "compact" models, apparently were designed/intended to sacrifice springs to achieve functionality not otherwise possible. This is true with both mags and recoil springs in compact and sub-compact guns.

Amin Parker: if you've been stretching springs with great success for years, tell us what sort of gun mags you've done this with. And how frequently you find it necessary to stretch them. Do you use these springs in a carry gun?

Typically, stretching a spring will just accelerate its decline. (As JohnKSa notes -- it's an emergency step, when you don't have any other alternatives.)

The problem seems only to be noticeable in hi-cap and sub-compact mags, which 1) put more rounds into a standard mag, or 2) try to put a lot of rounds into a space that generally is quite small. Springs, in both of these cases, must be compressed to the maximum.

As JohnKSa notes, rotating mags doesn't really solve a problem. Springs don't heal with rest. When rotating springs -- which isn't a bad practice -- all you've done is spread the use wear over a larger number mags. That lengthens the period between replacement but you have not increased the service life a given magazine spring; you're just using it less often.

If never having to replace a spring in a compact of high-cap mag is your goal, get 50 mags for the gun in question, and rotate them regularly. You may not have to replace any springs in your lifetime, but somebody will eventually have to replace those mag springs if they continue to be used.

For guns like a 1911, you may never have to replace a 7-round mag spring, ever... Same for most full-size 10-round mags. (Handy, if you're shooting IDPA.)

 

[Knite7]

Spring Myths

Stretching a spring does NOT damage it. That is how the spring is initially formed. (Starts out close wound, a "pitch piece" moves out while it is coiling to give it the correct length.
Feel free to stretch out any compression spring, but then Stress Relive it (heat) at 400-500 F for 45 minutes.
The problem that you will have with oval shaped magazine springs of course is that they will "fan" when stretched causing friction against the sides of the magazine.

Former Chief Engineer Gemini Spring Company
Knite7

 

[Bill DeShivs]

Knite7
Perhaps you could share more of your spring wisdom with us. What steel did you use for your springs?
What does Gemini make springs for?
Tell us about elastic limits.

 

[imthegrumpyone]

This is stretching things a bit, "Spring Steel" They are made to be fully compressed or or not, will not lose it's retention if aloud to be fully compressed in fully loaded magazine indefinitely. People do a lot of things they don't have too, and don't do any apparent damage, but stretching magazine springs are not a good idea.

 

[Amin Parker]

Walt.

I bought magazines in bulk. Some were in bad shape and i refurbished them. I use these mags for practice with great success. There is one 23 shot mag that is still troublesome. I put a sticker on it and use it for personal protection drills when i want to clear jams in a hurry.

In my experience, stretching springs does extent the life and reliability of magazines. The trick is not to try and stretch it to much. Maybe about 30%to 50% of current size

 

[Walt Sherrill]

Feel free to stretch out any compression spring, but then Stress Relive it (heat) at 400-500 F for 45 minutes.

How many of the spring-stretching advocates here, do you think, stress relieve their stretched springs with 45 minutes of 400-500 degree heat? (Would the optimal temperature used be dependent upon the metal used?)

And are the springs you're talking about stretched, during production, BEFORE or AFTER heat treatment?

 

[Slamfire]

Springs have an elastic limit. When it is exceeded either in compression or extension, then the spring will no longer operate at the original spring rate...it is ruined.

Why do springs take a set? I am thinking of mainsprings, because they do take a set, but the same would apply for magazine springs.

This begs the question of, does leaving a magazine fully loaded stress the spring so it loses spring tension?

 

[Bill DeShivs]

No- it shouldn't.

 

[Single Six]

Wow, I wasn't expecting to generate this many responses on this one. Anyhow....As a P.S., I should also say that, while the mags in question are failing to lock open the slide until stretched, they DO still have enough spring tension to feed reliably. Also, as I stated previously, I prefer to download by one round; I've found this to pretty much alleviate the problem...BUT, our range officer ripped me a new one when he found out I was doing it. Seems he felt it could be a liability issue [I'd go into how he explained that, but it's kind of a long story].

 

[JohnKSa]

Stretching a spring does NOT damage it. That is how the spring is initially formed. (Starts out close wound, a "pitch piece" moves out while it is coiling to give it the correct length.
Feel free to stretch out any compression spring, but then Stress Relive it (heat) at 400-500 F for 45 minutes.

A spring can't function properly as a spring until it's been properly heat treated. Yes, it's possible to stretch a piece of metal that isn't yet a spring but WILL become a spring (once it's been properly heat treated) and not damage it, but once it's a spring (after it's been heat treated) stretching it past the point of deformation will damage it. It will be weakened unless it is heat treated again.

I understand what you're saying but it's like saying that getting a plastic part up to the melting point won't harm it because it got to the melting point during the manufacturing process. Sure it did, but AFTER that point there was a critical operation that made the part actually useful--it was molded into shape.

Similarly, a piece of metal that is soon to be a spring may be stretched, but AFTER that point there is a critical operation that makes that piece of metal actually useful as a spring--it is heat treated.

In my experience, stretching springs does extent the life and reliability of magazines. The trick is not to try and stretch it to much. Maybe about 30%to 50% of current size

It may increase the reliability of the magazine for awhile and if the magazines are not working properly, it may increase their life a little (by getting them working again for awhile), however if you deform a spring and don't heat treat it again you've damaged it and it won't be as durable or as strong as it once was.

I am confident that if you get good quality replacement springs and compare their life and reliability with the stretched springs you will find that the stretched springs are inferior.

This begs the question of, does leaving a magazine fully loaded stress the spring so it loses spring tension?

There's nothing magic about magazines or magazine springs. Same rules apply. If the magazine design compresses the spring to the point of deformation when the magazine is fully loaded then the spring will lose tension/weaken/take a set over time from being left fully loaded. If it doesn't compress it to the point of deformation then it shouldn't be a problem.

 

[Knite7]

Spring Myths

To answer some of the questions.
First; Coiled springs are NOT "heat treated". They are formed from full hard materials and than "stress relieved" to remove the residual stress from the coiling operation. The vast majority of spring materials get their properties from being being cold worked, that is drawn through consecutively smaller diameter dies. The exception are the oil tempered materials like Oil Temper MB. However this is done at the mill and once again we are working with full hard materials, roughly 55 to 65 on the Rockwell "C" scale.
Some of the most common materials used are music wire, HDMB, 304 stainless steel, OTMB, chrome silicone and chrome vanadium.
Stress relieving temperatures will go from 250 to 850 F depending on type of material and working stress levels with 450 F being the most general.
I was one of the primary vendors for the M16 magazine springs, of which we produced close to a million. The material in that one was something called 17-7ph stainless. This material, the wire companies claimed, was suppose to have the tensile strength and yield of music wire, but with the corrosion resistance of stainless steel.
They exaggerated (lied) and some bureaucrat in Washington believed them, and that is why we had to load our mags 1 or 2 rounds shy of full.

Knite 7

 

[Bill DeShivs]

Well! This may very well explain why everyone says their springs "get weak."
Springs used to be wound from high carbon music wire, hardened and then tempered. These are the springs I am used to dealing with, and the don't get weak-they just keep on working.
I don't understand how you could wind 60 RC wire without it breaking?
304 is a lousy material for springs. It can only be hardened by work-hardening, and it will keep on work-hardening until it breaks.
It appears that spring making has changed quite a bit-and for the worse. It appears that ease of manufacture and price have seriously compromised the product!

Now I will say again what I have said many times- properly made and designed springs don't get weak.

 

[JohnKSa]

Coiled springs are NOT "heat treated". They are formed from full hard materials and than "stress relieved" to remove the residual stress from the coiling operation.

You have correctly stated twice that they ARE treated with heat (250 to 850 F) after being formed. I'm not sure why you believe that Stress Relieving is not a "heat treatment".

On the off chance I completely jumped the track I did some checking. All the sources I can find confirm that heat treatment is a generic term that encompasses not only tempering and annealing but also stress relieving and other generally similar processes.

It appears from your posts that you are trying to say that not all coiled springs are "tempered". It's clear that they ARE heat treated

 

[Slamfire]

You have correctly stated twice that they ARE treated with heat (250 to 850 F) after being formed. I'm not sure why you believe that Stress Relieving is not a "heat treatment".

On the off chance I completely jumped the track I did some checking. All the sources I can find confirm that heat treatment is a generic term that encompasses not only tempering and annealing but also stress relieving and other generally similar processes.

It appears from your posts that you are trying to say that not all coiled springs are "tempered". It's clear that they ARE heat treated

I would call it stress relief. It is obvious that the heat is being used to relieve stress within the material, stresses acquired during working of the material.

The heat is not being applied to raise the hardness of the steel material nor is it followed by a quench to fix the steel crystalline structure of the steel material.

 

[JohnKSa]

The heat is not being applied to raise the hardness of the steel material nor is it followed by a quench to fix the steel crystalline structure of the steel material.

That's a couple of types of heat treatment.

Some processes (probably not a complete list) that fall within the definition of heat treatment are annealing, hardening (including case hardening and precipitation strengthening/hardening, etc.), normalizing, tempering, quenching and stress relieving.

http://www.wisoven.com/technical/heat-treat-definitions

http://www.riheattreating.com/heat-treating-specialties.html

By the way, there's an error in my earlier post. The last line should read.

It appears from your posts that you are trying to say that not all coiled springs are hardened and tempered after forming. It's clear that they ARE heat treated.​