Educate me on Recoil Springs

gobsauce said:

I've read a few posts about folks replacing the factory spring for either a lighter or heavier one. Why would you do this? I understand replacing a worn out spring, but why change the spring to one with a different spring constant?

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Using a 1911 as an example, just because you need a starting point.

For instance, the standard recoil spring weight for a Government size (5" barrel) is, I believe 16 lbs. That gives you pretty good function with standard 230 gr. ball ammo at 850 fps. If you want to shoot low powered, lightweight target ammo, like 200 gr. semi-wadcutters at 700 fps, you may need a lighter recoil spring to properly cycle the slide with that low powered round. On the other hand, if you have a very tight gun, like a Les Baer, with 230gr ball, you may need a stronger recoil spring to make sure your slide returns to battery, if your gun is a little dirty or dry.

There is also some variance in power in factory 9mm ammo, if your 1911 is a 9mm gun. The 1911 slide is pretty much the same whether it is a 9mm, .38 Super, .40 S&W, 10mm, or .45 Auto. The recoil impulse is different between all those rounds, so a recoil spring is the thing that allows all those rounds to work in a gun that is designed for the .45 Auto recoil impulse. If you're shooting nothing but +P 9mm in 124 gr or 147 gr, one weight may work, but if you normally shoot cheap 115 gr training ammo, that is often pretty low powered, a typical 9mm 1911 recoil spring may be too strong to allow that lightweight ammo to properly cycle the slide.

In a gun like a Glock G34, which is probably set up to handle +P defensive ammo, the guys that are using the G34 as a competition gun probably aren't running defensive type ammo in competition.

They probably use reduced power ammo, which may not properly cycle the stock G34 spring, so they use a lighter spring. In addition, a heavier spring may slam the slide forward causing the muzzle to dip. The lighter spring won't slam the slide forward as forcefully, which may give them a flatter shooting experience, and allow them to keep the sights aligned better.

I'm far from an expert on the subject, but my understanding is that substituting spring weights is to balance reliable function, with mitigating the effects of slide velocity (and therefore wear on the gun).

If you're shooting a powerful load, the slide can come back with more force than is necessary to cycle the gun, and this extra force is battering the interconnecting parts (frame, locking block, and barrel lug). A heavier spring will reduce this.

If you're shooting a lower powered or reduced load, the spring may be too powerful for the load to reliable cycle the gun. A lighter spring reduces the resistance, so reliable function can be attained.

ETA: This balance can be seen in guns of the same make but with different barrel lengths. A shorter barrel has a shorter slide, which has less mass and therefore less inertia to overcome. So typically, a gun with a shorter barrel has a heavier recoil spring than the same design with a longer slide and barrel.

You can also observe a difference in spring weights based on the type of action. A 1911 or a Sig P229 both have a hammer spring to overcome for the slide to move to the rear. But a Glock does not. So for the same cartridge chambering and barrel lengths, the weight of the recoil spring is lower on hammer fire guns than striker fired ones. At least in my experience.

gobsauce said:

And how do I know that this is happening? Any telltale signs?

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I know that there are signs, but I don't know specifically what to look for. I believe peening and wear marks on the barrel lug and locking block are some of those. But I think others will know better.

The way I personally look at it is this. If I'm shooting ammo that is either factory, or not particularly powerful for the cartridge, the stock springs should suffice.

gobsauce said:

And how do I know that this is happening? Any telltale signs?

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What gun are you shooting?

Generally unless it is a race gun, 1911 or some other comp guns and you are tinkering with handloads, there is no need to change a recoil spring from factory standard

Some of it is simple tinkering--meddling with things just to meddle.
There's plenty of legitimate reasons for adjusting--as noted above--but you are making a narrowly-adapted firearm when you do.
Which is fine when running a "race" gun, which is meant to operate in a narrow range of uses, that's fine.
If a person had, say, a machine pistol, where heavy springs would seem to be necessary, but, that's also a "single use" sort of carry, too.

Generally, 80% of the world never needs even worry about such things.

Recoil springs generally never wear out in a person's lifetime, nit unless you are running more than 50 or 100 thousand rounds through a given firearm a year.

I would not install a substitute recoil spiting in a pistol because the O.E.M.spring is what the manufacturer deems appropriate for use with power range that will meet the resistance necessary for a wide range of ammo types. I understand reducing spring tension for weaker ammo, but I do not ever shoot low power ammo. I do not shoot +P+ ammo because Ruger did not build my model gun fir that power. I stick with original parts in my gums.

gobsauce said:

And how do I know that this is happening? Any telltale signs?

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If your gun is tossing empty cases three or four lanes over, you may have too light of recoil spring.

If your gun is having trouble ejecting cases, you may have too strong of a recoil spring.

I suspect people that shoot a lot, like a Rob Leatham, can probably tell you what weight recoil spring is in their gun just by feel, because they've tried just about every combination to get their gun to shoot the way they like.

My all-original, beautiful "Made in W Germany" Walther PPK/s constantly malfunctioned with our weak, modern "lawyer" .380 ammo. This ammo didn't have the blowback force to reliably extract cases from the chamber. Fail To Extracts were really frustrating.
A weaker, specific # Wolff spring, the type recommended on Walther Forums, made it very reliable.

Both of my .22 handguns --- bought brand-new retail --- had the same problem: an M&P standard length, and a new Ruger Mark IV. This lasted for over 1,500-2,000 rds. in each gun.
The main problems were with Federal bulk Automatch and the bulk "blue" box Federal brand.

But not even CCI Minimags were perfect. That seemed strange. ...........There was no limp-wristing in these or the Walther.

Careful reading informed me that cutting away a specific amount from each gun's recoil spring would help the slides blowback with more energy (less resistance) to help cases extract/eject.
Their function now is perfect. Like night and day. All of these guns mentioned are finally as reliable as my 9mm types: S&W 3rd. Gens, Sig P225 (German proofmarks), Walther P99 and CZ PCR.

Besides the issues already mentioned, you need to consider that all springs are NOT created equal. Some brands just coil spring wire to shape. This is not the most reliable or longest lasting method of spring making, but it is the cheapest. A better method is to form the spring, heat treat and shot peen the spring followed by thermal stress reliving. This is the better method, but it's more expensive.

Also consider possible guide rod failures. I've heard of problems with plastic guide rods. Tungsten guide rods are heavier than steel and they can reduce muzzle flip a little bit.

The Sig P365 recommends replacement of their recoil spring assembly after only 2,500 rounds. This seems like way to short of a lifespan. From what I've been led to believe, Sig does NOT heat treat, shot peen, or thermally stress relieve their recoil springs AFTER forming the springs. But worse yet, I've seen 6 cases of the Sig P365 recoil spring coiling over itself and causing a jam after as little as 200 rounds.

So I'm on a quest to find a more reliable recoil spring assembly. ISMI makes recoil springs that are heat treated, shot peened, and thermally stress relived AFTER forming. It is also a flat wound spring that by design would be virtually impossible for it to coil over itself. I bought a Rival Arms recoil spring assembly that uses an ISMI recoil spring. It's rated for 5,000 rounds, double that of the Sig RSA. They claim that it has an "Ultra Smooth" stainless steel guide rod. When I racked the slide it sounded like I was dragging my fingernails across the grooves of a phonograph record. It turns out that they just turn the guide rod on a lathe and call that ultra smooth. But even worse, I heard a report of a guy that had their guide rod unscrew by itself. I made a spring compressor to compress the ISMI spring so that I could disassemble the guide rod to polish it. I was able to unscrew it with my fingers! The threadlocker that they used did NOT cure properly!

Many people are unaware that in order for Loctite to cure it not only requires the absence of oxygen, but it also requires contact with an active metal such as copper or iron on at least one of the threaded surfaces. Regular Loctite will not cure properly with stainless steel, black oxide coated steel, or zinc plated steel. In those situations you must either apply a primer to the threads and let it dry before applying the Loctite, or buy the special formulation of Loctite that already has the primer inside.

It didn't take very long to polish the stainless steel guide rod. I bought some Loctite with the primer inside, applied it to the end cap threads, screwed it together and it appears to have cured. I'll be going to the range this week to test the recoil spring assembly. If it works well with the 5 different brands of ammo that I have, I will carry with the Rival Arms RSA with the ISMI spring and then use the stock Sig RSA for target practice where a failure won't be an issue.

The only gun I ever changed the factory strength recoil spring on is my well used when I bought it Tanfoglio "Mossad" 9mm. The slide fit is amazing, especially as well used as it seems to be. When I got it, it was slamming against the slide stop so hard I could feel it and hear it. I compared it to another of my Tanfo guns and it was obvious the spring was shot. I ordered a set of recoil springs from Wolff and the gun seemed to like the next # up spring, I think it was 15 pounds, and it still has it in it. When I tried to put the same # spring into any of my other Tanfo guns, which are pretty much identical, I had problems, so back to stock they went. All my other guns have stock recoil springs, regardless of design/make.

9mmepiphany said:

The twisted OEM springs (often mistakenly referred to a "wound") have designed-in recoil handling properties than cannot be duplicated by non-twisted springs

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The multi-wire twisted design can also cause as many problems as it cures if the manufacturing quality isn't well above average.

Other than adding some damping characteristics, I don't see that they are that much superior to plain wire springs. You can also add damping qualities by using one counterwound spring inside another with a slight interference fit.

If I am going to lay odds on reliability, I'll go with a known superior manufacturing process, such as forming the coil first, heat treating and shot peening followed by thermal stress relieving.

But as spring making is as much art as science, the manufacturing quality is often more important than the actual spring design.

I learned my lesson with replacing recoil springs. My dumb self thought it would be a good idea to replace the recoil spring in my Smith and Wesson 411 with a more powerful Wolff recoil spring. It caused my mag follower to get chewed up so the slide wouldn't lock open on the last shot. I put factory springs back in and all is well. The lesson I learned... if the gun is reliable, don't mess with it until it isn't reliable.

9mmepiphany said:

One should follow the manufacturers recommendation on scheduled spring replacement for designed reliability and peace of mind.

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Sure... but how many manufacturers put the info in the manual? It seems rare at best.

None of the guns I have included the info

danez71 said:

Sure... but how many manufacturers put the info in the manual? It seems rare at best.

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Sig buried the RSA replacement in the cleaning and lubrication section of the manual. But they should post a replacement schedule for all parts that need periodic replacement.

I bought a spring force gauge that I'm using to monitor the recoil spring force and also magazine spring force. The RSA that I use for carry will have a very low round count. I'll use the stock RSA for target practice and I'll measure the spring force when it starts to malfunction.

Eventually all springs will break. However, I believe that the recoil spring in my Sig P365X is more likely to become too weak long before it breaks.

9mmepiphany said:

Which guns would those be?

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Ones I have or had that readily come to mind of the semi auto handguns genre ...

Colt 1911 mark 4 Govt series 80
BHP mark 3
M&P9c 1.0
M&P Shield 9mm 1.0
Bersa thunder 22lr
Browning Buckmark
Ruger SR22

I could be wrong but I don't think any of them have a recoil spring replacement schedule on thier respective manufacturer website.