Weak Recoil Spring??

[Corona]

I am curious...several questions about recoil springs and when to replace.

How do you know when to replace a recoil spring?

Can a weak spring lead to accuracy issues?

When you replace the recoil spring is there any issue with going with a spring that is slightly stronger than original spec?

Thanks. Just hoping to tap into your collective wisdom.

 

[wpsdlrg]

A) The only way to "know" when to replace a recoil spring is when function degrades on a particular pistol. An example of this would be : the slide begins "slamming" against the stop (or locking block, etc.) thus creating a pronounced vibration which you can feel. If let go until this sort of thing happens, damage could result - so it is considered best to go ahead and replace the recoil spring before this happens. So, generally speaking, most people replace at 3000 - 5000 rounds, depending on the loads used (more powerful loads = earlier replacement).

B) Yes, accuracy can be affected, somewhat. However, accuracy may or may not suffer with a weak spring. Function WILL suffer - such as the aforementioned problem in paragraph A.

C) Going to a stronger or weaker recoil spring is dependent on the loads used. A "stronger" spring will NOT necessarily last longer, so forget that idea. A stronger spring is needed IF stronger loads are used - a weaker spring is needed if weaker loads are to be used. Going to a stronger spring, then using the same loads as before (with which the standard spring was adequate) will often introduce malfunctions. Put simply, the recoil spring must be balanced for the loads to be used.

 

[Walt Sherrill]

B) Yes, accuracy can be affected, somewhat. However, accuracy may or may not suffer with a weak spring. Function WILL suffer - such as the aforementioned problem in paragraph A.

re: Weaker recoil springs leading to accuracy issues..

I notice you said, "somewhat." I'm posting a disagreement with the comment above, but will happily accept corrections or comments to the contrary -- as I may be overlooking something very fundamental. That said, I agree with most of your other points.

With aimed fire, barrel to slide fit and consistent lockup are the key factors in assuring accurate fire. If you're doing a Ransom Rest test, then tight slide to frame fit matters, too -- but that's not aimed fire.

As I understand it, about the only way a weaker recoil spring could affect accuracy is that if the spring was so weak that it prevented proper or consistent lockup. If it's that weak, I suspect that proper function will likely be affected, too.

Except for assuring the same starting point for each shot (lockup) the bullet is generally out of the barrel before the slide has moved far at all -- and with some guns (and shorter barrels) before the barrel has begun to unlock. Given that, I don't see how a weak recoil spring can have a big role in accuracy after the trigger is pulled. But, as I said above, I may be overlooking something.

A couple of professional shooters I know often use very weak recoil springs, shock buffers, and other devices to INCREASE slide speed, but still keep overall function the same. These guys are shooting loads that are on the low end of what is allowed. The weaker springs and shock buffers, and sometimes recoil systems tweaked for proper function, helps reduce muzzle rise while increasing the slide's speed and cycling rate. In those cases, the weaker springs don't really affect accuracy, but do affect the speed with which the shots can be delivered. If you have the reflexes of some of the top shooters, that matters.

Recoil springs affect the recoil impulse: heavier recoil springs make it longer (and, arguably, easier to tolerate); weaker springs making it sharper and less long. A stronger recoil spring will retain more of the recoil force, and send more back to the gun as the slide closes; a bit more of the recoil force will pass through the gun into your hand and arm if the recoil spring is lighter.

A too weak recoil spring will have some obvious consequences, including any of the following. There may be others:
1) the spent cases will go into the adjoining county
2) the felt recoil will be different -- if only because less of the recoil force is stored in the spring.
3) the spring isn't able to store enough force to chamber the next round and close the slide.

A too strong recoil spring will have some obvious consequences, including any of the following. There may be others:
1) the spent cases will almost fall out of the gun -- if the gun still functions properly.
2) the felt recoil will be different -- because the recoil impulse will be lengthened, making it feel differently.
3) the slide won't open far enough to eject the spent casing or catch the, or the spent case won't be able to hit the ejector, etc.
4) Too heavy a recoil springs, with some guns, can make releasing the slide a bit of a chore. (See Note, below.)
5) A heavy recoil spring can also pass more (stored) force back to the frame, and in some designs, to the slide stop -- with it the potential for damage there or where the stop passes through the frame.

The main function of the recoil spring isn't to manage or reduce recoil (thereby protecting the gun) but to operate the slide -- stripping the next round from the magazine and causing the slide to push the round into the chamber. Depending on the gun's design, the recoil spring may have a "protective" function, but damage from too much recoil is more talked about than seen. When such damage is seen it often seems to be a design problem or production error.

There's a big range of "workable" spring strengths that will allow most guns to function properly, and the biggest differences you'll notice is how far the spent cases are sent or how the recoil feels in your hand. (Back when I was shooting a LOT, I used anything from 12 lb. to 22 lb. recoil springs in my CZs, and really didn't notice much change in function -- but the heavier recoil springs made it a lot harder to rack (and sometimes to release) the slide.

Note: Heavy recoil springs and slide release function:

With some SIGs I've owned, one of them a P226 X-FIVE in .40, the recoil spring was so strong that it was difficult to rack the slide and almost impossible (for me) to release the slide using the slide stop/release, unless I also pulled back on the slide. Forget a quick press of the thumb.

After I talked to SIG, they sent me a much lighter recoil spring, and that improved things quite a bit, but didn't make it all better. (The X-Five has a different recoil spring assembly than other P226s, and you can't just swap springs out using Wolff Springs.) I had a similar but less difficult problem with an early-production SIG P220 Super Match, the SA version of the P220.

I later sold both guns to a local shooters (a fellow Carolina Shooter's Club Forum member) who shoots competitively [USPSA]; he does his own gunsmithing, and does it well. He later commented that both guns -- which were strictly stock -- seemed badly over-sprung. He later said he found the X-Five to be not quite what he wanted, and sold it; but after doing some work and installing new springs, he loves the P-220 SM -- It's his everyday carry weapon.

.

 

[rt11002003]

Interesting conversation, especially the lighter recoil spring vs the heavier. It leaves me with questions. I understand force cannot be destroyed, but can be transferred. The round produces X amount of force. Some propels the bullet, some becomes recoil. Are we saying the recoil force is being absorbed into the springs, or even the gun? If so, how does the force get out? I'd like to see vector analysis of this action. Is there a source showing the force transfer? It seems to me that the recoil force can only go into moving the gun through the air, or into the shooter's body resulting in some movement.

 

[T. O'Heir]

Liked wpdlrg says, a spring that is slightly stronger or less strong is about the ammo used. The spring's job is about controlling the speed of the recoiling slide, not controlling force.
Stronger loads usually means heavier bullets(that whole equal and opposite reaction stuff), but it can also apply to light bullets going faster. Not so much about accuracy except as it applies to function.

 

[Bill DeShivs]

Here is my advice:
There is probably no need to change your recoil spring, unless your gun's manufacturer recommends it.
Changing spring weights was done by competitive shooters to tailor a gun to a particular load. The manufacturer knew the proper spring weight.

 

[Walt Sherrill]

I understand force cannot be destroyed, but can be transferred. The round produces X amount of force. Some propels the bullet, some becomes recoil. Are we saying the recoil force is being absorbed into the springs, or even the gun?

I'm not an astute physicist (not even a good amateur one), so detail proofs aren't something I can provide. (The following response is how I understand it -- or misunderstand it; someone more knowledgeable can set me straight if this isn't a correct explanation.)

When fired, some of the force of the recoil is absorbed by the recoil spring and is used to WORK the slide mechanism. In polymer-framed guns, some of of the recoil is retained by the polymer in the frame, which acts like a very stiff spring. (The fact that the frame flexes slightly is why few polymer-framed guns are tested using Ransom Rests; there is no absolute certainty that the frame will return to the exactly same place with every shot. With a metal frame, there's no option -- steel will flex a little, aluminum not much at all. The steel will return to it's original position*.

*(Amended in response to later comments by James K.)

Some (all?) of the remaining recoil force is passed on through to the gun's frame and then to your hand. Your hand is the solid based required to make it all happen. With stronger or weaker springs, the IMPULSE (the duration/period of time during which the recoil force is experienced) has changed, but not the total amount of recoil being handled.

Some recoil is experienced immediately, but a part of it is delayed as it's stored in the spring; some of it is experienced later, when the slide slams shut. Even the hammer spring, in a hammer-fired gun is absorbing and holding some of the recoil force, which is also released later, when the hammer is released with the next shot. Some of the force in the recoil spring when it returns the slide is converted to work, stripping around and chambering it. (With some of the striker-fired guns -- and some hammer-fired, too -- the force of the slide going to the rear will partially or fully cock the striker or hammer spring for the next shot -- a small amount of the recoil force is working there, too.)

The force passed from the chemical explosion to send the bullet forward is matched by an equal force passed to the rear, powering the slide and barrel. I'm pretty sure, however, that how those opposing forces are felt and experienced (and measured) at different rates by the person experiencing the recoil, depending on the strength of the recoil springs. Assessing those subtle differences will take measurements and explanations I can't provide.

If you took the recoil spring out -- the same forces would be there, but almost none would be converted to work to power the slide function, and only a little to power the hammer or striker springs (if that applies), so I guess the bulk of the recoil force (rearward) would go THROUGH the gun to the holder's hand, and through the arm, etc.

1911Tuner a participant here (and a moderator on several forums) has done this any number of times, with witnesses, using 1911a1 semi-autos. It might be interesting to see whether HE thinks recoil springs have much effect on accuracy...

1911Tuner removes the recoil spring and fires the gun. The gun functions, the round is fired, but it just doesn't have any way of cycling the next round. The frame isn't destroyed and, surprisingly, the shooter doesn't really notice that much difference in felt recoil -- arguably because only the recoil IMPULSE has been changed (less delay with no spring in place), none of the recoil stored in the recoil spring to later do the work of returning the slide and loading a cartridge, or charging the hammer or striker spring.

In another discussion, addressing the .357 SIG round, it was obvious that recoil springs are also used to control slide VELOCITY -- and that can be done with heavier slides, too. (The P228 was first tried -- by SIG -- in .357, but they found that a spring strong enough to handle the velocity was just too stout for many people to rack the slide; they went to other changes including a heavier slide, and that resulted in the P229.)

.

 

[Snyper]

If the gun throws the brass more than 6-8 ft, you could probably use a stronger spring

 

[Corona]

Gentlemen - my thanks for your knowledge and the extent of the information you all have provided. Walt, thank you especially for your discussion. Lots of information to process.

Dan

 

[1911Tuner]

re: No Spring

You rang?

http://rangehot.com/firing-1911-without-recoil-spring-nothing-broke/

 

[James K]

As usual, a misunderstanding of how a recoil operated pistol works. Using a 1911 as an example, when the cartridge is fired, pressure begins to build but nothing moves. The barrel and slide are locked together just as solidly as the bolt on a Mauser rifle is locked into the receiver.

When the pressure builds enough to force the bullet to move, its motion forward results in an equal and opposite force to the rear. If the bullet does not or cannot move, nothing happens and the slide (and gun) will be motionless. Saying that the pressure pushes the slide back is not correct. The barrel and slide recoil locked together, just as the Mauser rifle stays locked until the user opens the bolt. If nothing intervenes, they will stay locked together. But as they recoil, the link pivots and pulls the barrel down, out of engagement with the slide. The barrel then stops on the frame, while the slide, on its own momentum, will continue to the rear, extracting and ejecting the empty case. The slide will stop on the recoil spring guide, transmitting its remaining force to the guide and the frame. When the slide momentum dissipates, the recoil spring will reassert itself and its power, along with the force stored in the frame, will throw the slide forward to pick up a fresh round, chamber it, and go back into battery.

Note that business about the frame restoring momentum to the slide. Another way to put it is that the slide bounces off the frame. If that energy is absorbed, as by a buffer, the slide may not have enough momentum to return to battery and a malfunction can result.

Jim

 

[Walt Sherrill]

... along with the force stored in the frame

Please explain that point a bit more. I added the underlining. I've not heard that particular phenomenon discussed before. (I know that steel will flex a bit, aluminum hardly at all, and polymer a good bit... but seldom have heard of a frame as a source of stored force.)

 

[michael t]

I went to a 15lb spring in my KelTec 380 I think 13 better all around . But I shoot Corbon and BB so I used the 15 . Ejected cases stay in general area Not in orbit like weak factory spring I increased the P-32 also to 13 . It works better .

The 15 is little harder to rack that small slide. I haven't had no problems with loading or ejection . In either pistol.

I might return the 380 back to 13 lb if just shooting ball and hotter Corbon and BB now and then.

 

[James K]

Hi, Walt,

When any object hits a surface, some of its force is absorbed by that surface. But depending on the surface, that force may be totally absorbed (think a ball bearing dropping on a pillow) or may be partly returned (think the same bearing dropped on a steel plate). In the latter case, the surface (the plate) returns a good part of the stored force, so the ball bearing bounces. That is what happens in a 1911 (and most other auto pistols) and aids in feeding the next round and returning the slide to battery. High speed photos show that the time involved for the slide to return to battery after firing is much less than the time involved when the slide is simply released by the slide stop; the difference is that "bounce".

A buffer absorbs more of the recoil force, so there is not as much left to return the slide to battery; the result is that a buffer, intended to "protect" the frame, can cause malfunctions.

Incidentally, steel has a high elasticity. Remember those little gadgets with the steel balls hung in a cradle; they bounce for a long time, absorbing and passing on the force imparted by the end ball.

Jim

 

[Walt Sherrill]

When any object hits a surface, some of its force is absorbed by that surface. But depending on the surface, that force may be totally absorbed (think a ball bearing dropping on a pillow) or may be partly returned (think the same bearing dropped on a steel plate). In the latter case, the surface (the plate) returns a good part of the stored force, so the ball bearing bounces.That is what happens in a 1911 (and most other auto pistols) and aids in feeding the next round and returning the slide to battery. High speed photos show that the time involved for the slide to return to battery after firing is much less than the time involved when the slide is simply released by the slide stop; the difference is that "bounce".

I wonder how that "bounce" could be measured?

If I seem unconvinced -- and I am -- its because we're dealing with something I've not seen discussed before. (So forgive what may seem to be obtuseness... Or, maybe it is obtuseness. )

The fact that the slide returns FASTER than it moved back may have more to do with the nature of the load powering the projectile and the traits of the recoil spring than the energy that has been stored in the frame and returned. Then too, I know that some folks who shoot professionally tinker with lighter recoil springs and buffers to increase the cycling rate of a handgun with specific loads. Light loads and much lighter recoil springs, with buffers lets them fire much more rapidly with less muzzle rise.

Incidentally, steel has a high elasticity. Remember those little gadgets with the steel balls hung in a cradle; they bounce for a long time, absorbing and passing on the force imparted by the end ball.

I suspect that other materials, such as very hard plastic with similar weight, would act in a similar manner... as would something ceramic. I'm no physicist, as I stated earlier, but it seems like something more than "elasticity" is at play there. I wonder what would happen if those balls were made of an aluminum alloy -- seeing that aluminum doesn't flex as much or as well.

The force must still be transferred when the balls collide. And I would argue that it's the TRANSFER OF FORCE that makes those ball swing and swing and swing, and any force absorbed should probably be converted to heat as the metal flexed (and be lost, not returned.)

I agree that steel can flex and return to its former (internal, structural) state -- until it has been flexed too far. That is true of many materials -- steel is just better at it than most folks realize. The steel used to make springs is very flexible; but I wonder if the steel used to make frames, while flexible, isn't substantially different.

Aluminum, on the other hand, doesn't as flex well as steel. Yet I've seen after-market steel and alloy Glock frames. http://www.ccfraceframes.com/faq.php Does that suggest that an alloy-framed Glock is not going to pass back as much stored force as steel-framed Glock?

When I shot a friend's .500 S&W it HURT! The frame may have absorbed some of the force of recoil and sent it back (somewhere), but from my point of view, that frame was the ballbearing (and not the plate) and my hand was the pillow.

(With a later rereading of my comment immediately above, using a revolver instead of a semi-auto [with moving slide and recoil spring] isn't the purest example of my point -- I should have used a Desert Eagle shooting a .50 AE load -- I've seen it, but not experienced it. That said, I do genuinely question the role of a handgun's frame in storing and returning force during the firing cycle.)

 

[1911Tuner]

Bouncy

I wonder how that "bounce" could be measured?

Watch the video. It doesn't bounce. The slide stops when it hits the frame like a dead blow hammer.

 

[James K]

"The slide stops when it hits the frame like a dead blow hammer."

I don't think any "bounce" would show up in that video, partially because no one was looking for it. Maybe a more controlled and better recorded experiment is in order. Even so, the video shows that a gun without a recoil spring does not blow up, or open too soon and let the case burst, as many folks have assumed and said. I once said on one of these sites that the function of the recoil spring was not to contain the pressure, but to return the slide to battery, and that a pistol didn't need a recoil spring to work if returned to battery manually. Boy did I get the flak!

Jim

 

[1911Tuner]

Bouncy

I don't think any "bounce" would show up in that video, partially because no one was looking for it.

It didn't show up because it didn't happen. The slide hit the frame and stopped dead. And if the slide doesn't rebound without a spring, it surely won't rebound with one.

There might be a little bounce if the frame is locked in a vise...but not hand held. As they say: There's a little cushion for the pushin'.

Somewhere out there is a slow-motion video that shows the effects of different recoil spring rates. With all except the heavier springs...18 pounds and over...the slide impacts the frame and stops...and hesitates before it starts the return trip. With the 12 pound spring, the "hang time" is surprising.

 

[g.willikers]

For an attempt to answer Corona's original question of how to judge when a recoil spring should be replaced,
How about when the at rest length gets shorter than normal, and the coils become closer together?

 

[Walt Sherrill]

I once said on one of these sites that the function of the recoil spring was not to contain the pressure, but to return the slide to battery, and that a pistol didn't need a recoil spring to work if returned to battery manually. Boy did I get the flak!

We get into the same sort of discussions and misinformation when we talk about almost any firearm related topic.

I've been told that recoil springs are primarily there to make the slide do it's job, and the strength of the spring may vary to control slide VELOCITY, which can be affected by pressure. (But velocity can be managed by using a heavier slide, too.) Heavier springs are better in some cases, and heavier slides are better in others. Others ways of controlling velocity, such as buffers in some H&K handguns, can also be used. I don't think slide velocity was a big concern in the earlier stages of modern (non-black powder) ammo development, but with some newer rounds and loads, it might be... (The .357 SIG round immediately comes to mind...)

Aquila Blanca, citing 1911Tuner in another discussion on this forum noted:

Lastly, 1911Tuner has mentioned innumerable times that Browning's patent for the M1911 does not call that round spring in the front of the pistol a "recoil" spring. It's an "action" spring, and its purpose is to close the action, NOT to resist recoil. The original design for the M1911 called for a "recoil" spring that was about 14 pounds. Then it got bumped to 16 pounds, and today we find any number of people who really should know better advising to use 18, 18.5, and even 20-pound recoil springs.​

Recently, here and on THE HIGH ROAD forum, the topic of spring wear and what causes it has been given much coverage. Some of those participating are engineers who work with the materials and springs being discussed. A couple of those participants over the past two years have included metallurgists. The "experienced" folks continue to argue with these experts, even though the experts work with the materials, deal with it on a regular basis and, as one of the forum moderators has done, provided test data. These experts (or knowledgeable laymen) can show all sorts of evidence, both practical and scientific, to back their positions. The response of the "experienced" folks is, "I've done this for years and never had a problem...so you can't be right."

Getting flak doesn't always mean you're wrong. A lot of folks have opinions -- and some of those opinions are informed, some aren't.

What prompted my comments in this particular discussion was the statement that recoil springs could have a possible (but probably modest) effect on accuracy. I still haven't seen that point addressed.

.