Heavy recoil springs for heavy loads (Wolff springs/Underwood Ammo)

[Snowdog]

I've decided to hold off on a 10mm for now and decided to use what I have for trail use. I've chosen to use my XDm 4.5 with 357sig Storm Lake barrel.

I have a few boxes of Underwood 357sig loaded with 125gr Gold Dots and pushed to an advertised 1475 FPS. After some google-fu, it appears that this load from a 4.5"-5" barrel routinely makes it to and beyond 1550 FPS. That's around 670 ft/lbs.
17 rounds at the ready of such ammunition sounds decent enough for the mountains of WNC. If not, I plan on toting 2 additional 16-round magazines to repel ne'er-do-wells and large furry/toothy things with claws.

Being I plan on putting a few of these down range, maybe 250 rounds or more to test function, I figured a heaver-than-stock spring would be a good idea. I purchased both a 20 and 22 pound spring to replace the stock 18 pound spring while using Underwood or Buffalo Bore ammunition. In the past, I've only used stock springs with Underwood (with perfect results).

Presuming reliability is still positive with the heavier spring, is there any caveat using heavier springs?
I know these hot loads will accelerate wear. I also suspect the heavier springs might offset some of the punishment dished out by these loads. However, being the action of the spring returns the slide to battery much harder than the stock spring, will this increase unforeseen types of wear or bullet set-back during cycling? I certainly don't want bullet set-back with Underwood ammunition!

I'm interested in hearing from those using heavy springs with hot loads. Have there been any mysterious issues encountered?

Thanks in advance!

 

[wow6599]

Presuming reliability is still positive with the heavier spring, is there any caveat using heavier springs?

Only thing I can think of is to remember to change the springs back to stock when going back to shooting "regular" .357 or .40.

However, being the action of the spring returns the slide to battery much harder than the stock spring, will this increase unforeseen types of wear or bullet set-back during cycling?

Interesting thought. Due to its short neck, I guess it could be a problem.
As someone with a G20 and a LW .357 barrel, I will be watching for answers.

 

[Drail]

Instead of using a heavier recoil spring use a heavier hammer spring. The hammer is what actually slows the slide down. The recoil spring plays a very small part in controlling the slide velocity. It only real job is to drive the slide forward again and strip a round from the magazine and force it into the chamber. With a heavy enough hammer spring you can run as light a recoil spring as you want and get less muzzle flip. (up to a point) Any ammo that sets back is defective. (unless you are rechambering the same round over and over - don't do that) If a factory round cannot chamber one or two times in ANY gun without any setback - it is an ammo problem - not a gun or spring problem.

 

[Sam1911]

It is an xDM -- striker fired. I'm not sure that a stronger striker spring will have any effect on the slide velocity as it isn't camming back a hammer. If it was a 1911 (or other hammer-fired gun) I'd agree -- and throw in the idea of a sharper radius on the firing pin stop -- but I don't think that's going to help here.

Now, I'm not sure a stronger recoil spring is the perfect answer either, but I don't think a couple pounds heavier is going to hurt anything.

 

[Walt Sherrill]

Drail has it right. The recoil spring doesn't really control or manage recoil, it operates the slide.

The recoil force isn't really all that great -- although it can seem so when you fire a gun. Most of it still goes through the gun into your hand(s), up your arm, and into your body, which explains why technique can make a difference when shooting. (You form the solid base against which the gun must react -- and changing a recoil spring by a few pounds doesn't really change the amount of recoil you experience much in absolute terms. A heavier recoil can change the recoil impulse and how it is FELT by the shooter, and some like heavier recoil springs because of that.

Recoil isn't hard on the gun. 1911Tuner, who participates here from time to time, demonstrates this by firing full-power .45 rounds in 1911s, with the recoil spring removed. The gun fires, the shooter doesn't notice a big difference; the slide doesn't close after the shot. Even though there's no recoil spring, the gun and the shooter aren't harmed.

A heavier recoil spring causes the slide to slam forward with a bit of extra force (due to the fact that the heavier spring is storing a bit MORE energy than the spring it replaced.) I don't think a heavier spring will affect the ammo in the chamber or magazine, and since the extra force (when the slide slams forward) is applied in the OTHER direction (forward), I don't think it would cause "setback."

However, with some guns, that extra force can accelerate wear on the slide stop and lead to breakage -- as it's really doing just that: stopping the slide, and it's a relatively modest piece of metal.

I try to use the lightest recoil spring I find comfortable to shoot, that allows the gun to function properly. If you reload, you may use a heavier recoil spring to keep the spent cases in the same county...

 

[Sam1911]

Drail has it right. The recoil spring doesn't really control or manage recoil, it operates the slide.

That part I agree with.

But, using a stronger mainspring (striker spring in this case as there is no hammer to cam back) I don't think is going to change the way the gun handles the firing energy.

 

[JDGray]

A stronger recoil spring will keep your brass from flying to the next county
I have a CZ40B, that you could feel the slide slap the frame every shot, so I installed a heavier spring cause it bugged me...

 

[Walt Sherrill]

Sam1911....

I was focused on what the recoil spring does, and paying less attention to the hammer spring part of the discussion.

I edited my response when I first wrote it -- as I tried to reshape what I was writing. When I did, I cut out a part about the striker-fired guns, as it didn't seem necessary.

Drail is right in that increasing the hammer spring weight will function in much the same way as installing a heavier recoil spring. That said, I really don't think that either the hammer spring, the recoil spring, OR the striker spring really changes things all that much. We're talking about a few pounds of spring weight tension, in most cases. I think the bulk of the recoil goes into the shooter's body.

I do think a heavier striker spring would, with most striker-fired guns, give you a slightly heavier trigger pull -- but that would be the case with a heavier hammer spring in many hammer-fired guns, too.

 

[Edarnold]

Another view about recoil springs in 10mm pistols. When I started working up stouter loads in my standard steel Witness I experienced FTF failures at a certain level. Ejection was complete and forceful, but the slide was running over the round before it could fully rise up in the magazine. My guess was that the slide was hitting the frame hard enough that it was bouncing forward faster than the magazine could feed the round. I substituted a 20lb Wolf spring for the 14lb factory original and the problem went away. The gun still functions fine with the 'mild' factory loads ( Federal American Eagle 180gr FMJ ) also functions perfectly with hand loads up to top level. And, please, don't tell me I need to fix the magazines, these are the same late model magazines that now work fine.

With all due respect, comparing what works for the M1911 to what works for a CZ75 clone is like comparing tuning for an M1918 BAR to what would work for an AR15. They are both auto loading weapons, and that's where the similarities end. I'm sure you could fire the Witness or a CZ without a recoil spring without breaking anything: in a word, so what? The hammer on the Witness, and presumably a CZ, does offer a lot of resistance to the the slide opening, but putting in a stronger spring there is also bound to increase the trigger pull, which is plenty heavy to begin with. A buffer would be an ideal solution, but most modern pistol designs don't allow enough slide travel to leave room for that extra piece. So the recoil spring can and will allow adjusting the slide velocity at the end of the recoil stroke to accommodate the recoil impulse of different cartridges. If you check Hennings page on Tanfoglio springs, you will see his recommendation is for matching the the recoil spring strength to the power level. Considering his extensive experience with this type of pistol, I'll take his recommendation.

 

[JDGray]

^^^I run 20# springs in all my CZs, even the compacts. Just gotta trim them to eliminate coil bind.^^^

 

[Pilot]

^^^I run 20# springs in all my CZs, even the compacts. Just gotta trim them to eliminate coil bind.^^^

So then they are not really 20 lb. springs, are they? What weight do you think they are now?

 

[Walt Sherrill]

...With all due respect, comparing what works for the M1911 to what works for a CZ75 clone is like comparing tuning for an M1918 BAR to what would work for an AR15.

And, on the other hand, recoil IS recoil and both guns, while operating at different pressure ranges, do use a variant of the Browning short-recoil system. My point was that recoil isn't necessarily destructive to the weapon, and a lot of people think it is.

When I started working up stouter loads in my standard steel Witness I experienced FTF failures at a certain level. Ejection was complete and forceful, but the slide was running over the round before it could fully rise up in the magazine. My guess was that the slide was hitting the frame hard enough that it was bouncing forward faster than the magazine could feed the round.

Another equally effective solution is to go to extra-strength magazine springs -- which raises the next round just a bit faster and a bit more forcefully. Wolff offers those, too. And they work just as well when you shoot less powerful rounds.

A buffer would be an ideal solution, but most modern pistol designs don't allow enough slide travel to leave room for that extra piece. So the recoil spring can and will allow adjusting the slide velocity at the end of the recoil stroke to accommodate the recoil impulse of different cartridges. If you check Hennings page on Tanfoglio springs, you will see his recommendation is for matching the the recoil spring strength to the power level. Considering his extensive experience with this type of pistol, I'll take his recommendation.

Nothing wrong with Hennings recommendations. As I said, use the lightest spring that lets the gun work properly. You may simply have to change recoil springs with different loads. Just going to a heavier recoil spring, however, isn't the solution for every round. And doing it to protect the gun -- the reason that many cite -- is arguably an invalid reason.

You recommend a Buffer, above. What, in your mind, is the intended function of a buffer. Why is it the ideal solution?

^^^I run 20# springs in all my CZs, even the compacts. Just gotta trim them to eliminate coil bind.^^^

And, by doing that -- trimming coils -- you've reduced the pound rating of the springs. How much, I wonder?

Coil bind (do you mean kinking?) can be reduced (in a CZ) by using Wolff's Browning Hi-Power recoil springs, which are a better fit than the Wolff springs for CZs. They're almost identical to the factory springs, and come in a greater range of weights.

The springs that Wolff sells for CZ are really Tanfoglio/Witness springs, made to fit the larger-diameter Tanfoglio guide rod; their larger diameter allows a lot of slop and (maybe) kinking. The Browning Hi-Power springs are an almost perfect fit.

I don't think Wolff has BHP springs for the Compact models, so cutting there would be necessary.

 

[hentown]

Instead of using a heavier recoil spring use a heavier hammer spring. The hammer is what actually slows the slide down. The recoil spring plays a very small part in controlling the slide velocity. It only real job is to drive the slide forward again and strip a round from the magazine and force it into the chamber. With a heavy enough hammer spring you can run as light a recoil spring as you want and get less muzzle flip. (up to a point) Any ammo that sets back is defective. (unless you are rechambering the same round over and over - don't do that) If a factory round cannot chamber one or two times in ANY gun without any setback - it is an ammo problem - not a gun or spring problem.

That's an authoritative-sounding post all right, except for the fact that the XD doesn't have a hammer. Maybe he should stick with plan "A" and go with a heavier recoil spring??

Per Wolff's guidelines: If that XD is throwing brass farther than about 8', then he needs a stronger spring.

Yeah, I wouldn't lose a lot of sleep about that XD's hammer slowing the slide down.

 

[Snowdog]

Well, since I already have both the 20 & 22 pound springs, I'll experiment I suppose.

Both the 20 and 22 pound Wolf springs also came with striker/firing pin springs as well. I'm hoping this means there's more resistance in setting or "cocking" the striker, thus slowing the speed of the slide's return. That's a guess and I'll have to read the literature that came with the springs to be sure. If so, I guess that might affect the trigger pull. Everything comes with a price, I guess this is no exception.

Thanks guys for the insight.

 

[Walt Sherrill]

Both the 20 and 22 pound Wolf springs also came with striker/firing pin springs as well. I'm hoping this means there's more resistance in setting or "cocking" the striker, thus slowing the speed of the slide's return.

With some Wolff Spring kits, the extra spring is a firing pin spring -- which is heavier to offset the extra inertial force of the slide slamming forward (which could, in guns without firing pin blocks, cause the firing pin to slam forward and ignite the next round). Most guns, nowadays have firing pin blocks -- and I never replace THAT spring.

I didn't know that Wolff also offered a striker spring in some kits -- and I don't understand why that would be necessary. I haven't replaced a recoil spring on any of my Glocks, and except for a LUGER (and maybe a CZ-100, ugh), they're the only striker-fired guns I've owned. (See below.)

(With the hammer-fired guns, an heavier spring is arguably necessary. But with striker-fired guns, I don't understand why they'd have a replacement spring -- as it's going to be compressed the same amount when the slide moves just a bit. In the hammer-fired guns, the extra spring is used to offset the motion of the slide, in theory at least; with Striker fired guns, a heavier spring doesn't seem necessary. Maybe there's something going on that's more subtle than my understanding of the mechanism.)

 

[JDGray]

So then they are not really 20 lb. springs, are they? What weight do you think they are now?

Don't really matter, don't really care, as they fixed the slap issue in my 40B, and keeps the brass a lot closer in the rest of my CZs. Never an issue with weak ammo, all slides lock back on empty.

I trim the springs until I can lock the slide open manually. Be it bind or kinkiness, that don't matter either...

 

[Pilot]

Don't really matter, don't really care, as they fixed the slap issue in my 40B, and keeps the brass a lot closer in the rest of my CZs. Never an issue with weak ammo, all slides lock back on empty.

I trim the springs until I can lock the slide open manually. Be it bind or kinkiness, that don't matter either...

OK, whatever works for you. I just wanted to make sure others know it isn't really a 20 lb. spring in case they want to install one without modification. I prefer installing springs that I don't have to modify, so I know what I am running, but that is just me.

 

[hentown]

The striker springs that come with Wolff's Glock recoil springs are standard-weight striker springs. Don't know about the XD. Might be the same. Info is probably on Wolff's website.

 

[JDGray]

I don't think Wolff has BHP springs for the Compact models, so cutting there would be necessary.

Yes, and the compacts (including the 40B) need trimming.
Will have to explore the BHP option next time

 

[Ramone]

And, by doing that -- trimming coils -- you've reduced the pound rating of the springs. How much, I wonder?

IIRC (please, someone correct me if I am wrong), clipping coils actually makes a spring stiffer, not weaker.

 

[Walt Sherrill]

IIRC (please, someone correct me if I am wrong), clipping coils actually makes a spring stiffer, not weaker.

I think you're wrong, but it is a confusing topic. For a given spring, if you reduce the number of coils -- as would be the case when you shorten the recoil spring -- the ability of the spring to do work is also reduced.

Here's a website explanation of how cutting coil springs in a car affects the springs ability to handle loads. While it's a car and not a gun being discussed, the ability of the spring to do work is what is addressed. In one of the examples in the article, they cut a car's coil springs by 2" (from about 6") and it's ability to absorb weight/move before bottoming out is greatly reduced. The whole article is quite good, with good examples. The section "Suspension Travel and Chassis Load" addresses this topic, but the rest is interesting, too.

http://craig.backfire.ca/pages/autos/cutting-springs

To have the ability to do the same work with a shorter spring, you must use a spring with a higher "spring constant" which means, in effect, a "stiffer" spring. An 18lb. recoil spring for a full-size gun and an 18lb recoil spring for a compact gun are made differently, perhaps from steel of a different composition or with a different diameter -- the compact gun's recoil spring is not just a shorter version of the fullsize gun's recoil spring, made from the same material and wound in the same manner..

In the example on THR, the shortened spring may be stronger than the stock spring it replaced, but it's weight (functional ability to resist compression) is lower than the spring from which is was created -- but in the THR case the shooter doesn't care, as he's happy with the results.

Note: some years back, before it was so easy to find replacement springs of different weights, one of the ways that home gunsmiths made trigger weights lighter on hammer-fired guns was to clip a coil or two off the mainspring (hammer spring). Not overdone, it worked pretty well -- but now that there are other options, I'd look to get a proper spring with a lighter weight.

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