Do heavier recoil springs reduce felt recoil?

[Recon]

A fellow shooter claims he has a 20lb recoil spring in his 5" 1911 instead of the usual stock 16lb. spring. He also claims that the heavier spring results in much less felt recoil.

Is his theory correct? Is there a downside to using a much heavier recoil spring such as increased wear, etc.?

[wichaka]

The downside is that the slide will slam forward harder, working on the barrel lugs and slide stop pin.

There's a reason why there's a 16lb spring specified.

Springs work both ways.........they may recoil slower, but what goes back has to come forward at some point!

[Candiru]

My experience has been that heavier springs actually increase recoil
by transmitting more force to the frame as the slide comes back.
Lighter springs have more of a slap at the end of recoil, but the push
is less during recoil.

[kel]

Heavier springs push the sights back down farther when the slide goes home and the muzzle tends to dip too far if the spring is too heavy.

[lanceriley]

20lb spring is I think too much. tried out an 18# once. the forward slam was already hard. what more a 20#

[John]

I can show you a barrel with broken legs, it came from the gun of a friend who used a 22 lbs spring. He said it improved his double-tap times. Yeap, he is now using an EGW firing pin stop and a 16 lbs spring. Oh a new barrel too.

[lanceriley]

I can show you a barrel with broken legs, it came from the gun of a friend who used a 22 lbs spring. He said it improved his double-tap times. Yeap, he is now using an EGW firing pin stop and a 16 lbs spring. Oh a new barrel too.
\

haahahaha i dont think it will help in double taps. but it did help him get a new barrel

[1911Tuner]

Springs work in both directions. The harder the spring resists...higher value...the harder it will release its stored energy. When the slide compresses the spring, the spring fights back, and pushes on the slide. When it pushes on the slide, it also pushes against the frame by an equal amount. Therefore...if the spring's compressed resistance is 16 pounds, it applies 16 pounds of force against both the slide and the frame...because the slide and frame make up an interacting action/reaction pair.

Newton-3 dictates that for every action, there is an equal and opposite reaction.

Therefore...If the slide is being pushed by 16 pounds of force in one direction, the frame is likewise being pushed by 16 pounds of force in the other direction. If they're being pushed by an 18 pound spring, they're being pushed harder.

Therefore...The heavier the recoil spring, the greater the felt recoil.

[John]

Amen! See, that's the good thing with Johnny, he can tell in simple terms things that would take me a page to explain. Thanks buddy!

[David Rose]

But... if the slide slams into the bedding area, that is perceived as recoil by many also. The greater the spring pressure, the less slam there is. Of course, the slam in the forward direction causes another "felt recoil" by some. So the heavier spring will increase that forward slam. That slam at the end of the rearward stroke can be sharp. But slam at the forward movement is more likely to cause damage to some part(s) or another. It is in the last few fractions of an inch that the slide stop pin engages with the barrel lugs and starts the barrel upward. Then you have slide lug to barrel lug engagement occuring. So you face a trade-off. I would stick with John Browning's ideals and idea, and stay with "stock" springs.

David

[carsten1911]

But... if the slide slams into the bedding area, that is perceived as recoil by many also. The greater the spring pressure, the less slam there is. Of course, the slam in the forward direction causes another "felt recoil" by some. So the heavier spring will increase that forward slam. That slam at the end of the rearward stroke can be sharp. But slam at the forward movement is more likely to cause damage to some part(s) or another. It is in the last few fractions of an inch that the slide stop pin engages with the barrel lugs and starts the barrel upward. Then you have slide lug to barrel lug engagement occuring. So you face a trade-off. I would stick with John Browning's ideals and idea, and stay with "stock" springs.

David

David,

You are very right on that one...my Springer suffered from weak springs out of the box: Besides annoying stoppages it had what you called "sharp slam"...it was pretty bad for a 1911, nearly like a 6" L-frame in .357 mag, not anywhere near what a pistol should feel like.
So the lower limit for springs is to be taken into account as well....

A 20 pound spring felt better, but learning the facts (from Johnny, of course :) ) I decided to just get a good 16 pound replacement and voila: everythings fine now, now and then I put in that small radius FPS, just to have a slightly different feel, but not shooting action I dont really need it. Recoil is very nice, just a good handful, not more.
But I might try a 14 pound spring with that FPS (when I get to shooting a lot more) to preserve the pistol even longer...

Never will I go outside the minimum of 14 and maximun of 16 pounds again!

Carsten

[David Rose]

Wife shot one of the recons I'm building today. She complained about *both* slide racking pressure *and* recoil. The gun has a 16# Wolff recoil spring and a 23# Wolff hammer spring. It does have a "standard" humongous radius FPS. On assembly, the recoil spring feels stiffer than the Colts in the display case. I have a spring gauge, so I guess I should measure the weight. Wife thinks recoil is more severe than our Colt Defender. ??? This seems odd. Or maybe it is just her perception. Or maybe it is velocity loss due to the shorter barrel on the Defender. We have not shot both one after the other. That might also put things into perspective. I think we both need to try them both at the same time.

David

[gbw]

I'll be very interested in that result, David. The Wolff standard spring seems a good bit stiffer to me also........I've seen Tuner mention in passing, several times, 'not to overspring the gun', usually in feed problem discussions. After playing around with the feed process a good bit, it finally sunk in why, and that this is one of his most valuable nuggets. I wish more folks would take it to heart. He should tattoo it across the top of this site.

As to perceived recoil, well, that's a very slippery slope around here. Everyones' perception is different, and fits the old Supreme Court Justices' comment on pornography: " I can't define it, but I know it when I see (feel) it. "

What I do know is that there is nothing, short of changing the weight of the gun or the power of the load, that will change the amount of recoil that ultimately ends up in the hand.

[Recon]

Thanks everyone for your contributions. Looks like 1911Tuner submitted the most authoritative info as usual.

I'll contact my friend with the heavy spring theory and try out his 1911 on the range to see what it recoils like compared to my stock 1911 setup.

Regards.

[David Rose]

gbw, I forgot to weigh the springs today. I made a note to do it tomorrow... if I don't forget to look at the note... :o

I'm pretty lean, except where my chest has settled to where my stomach use to be... I can enjoy shooting almost any handgun that I've tried. But a recoiling long gun turns me into a flincher with two shots. We all have different responses.

David

I'll be very interested in that result, David. The Wolff standard spring seems a good bit stiffer to me also........I've seen Tuner mention in passing, several times, 'not to overspring the gun', usually in feed problem discussions. After playing around with the feed process a good bit, it finally sunk in why, and that this is one of his most valuable nuggets. I wish more folks would take it to heart. He should tattoo it across the top of this site.

As to perceived recoil, well, that's a very slippery slope around here. Everyones' perception is different, and fits the old Supreme Court Justices' comment on pornography: " I can't define it, but I know it when I see (feel) it. "

What I do know is that there is nothing, short of changing the weight of the gun or the power of the load, that will change the amount of recoil that ultimately ends up in the hand.

[David Rose]

gbw,

I found a couple of interesting things. Two Colts, one an 80 series, the other a 90, both NIB, had recoil springs that weighed 13# plus or minus 1/4. That lead me to not trust the spring scale. So I grabbed a target rifle off the wall, weighed it on a known accurate postal scale, and found the spring scale to be off less than 1/4# at about 13#. After the marker was reset slightly, the spring gauge gave 13# on one and 13 1/4 on the other Colt spring. The Wolff springs marked as 16# showed about 16 1/2#. So if the spring gauge is off, it is still showing considerable difference. Is Colt listening to Tuner?

Sorry if any of this is unclear. Writing in a rush at work.

David

I'll be very interested in that result, David. The Wolff standard spring seems a good bit stiffer to me also........I've seen Tuner mention in passing, several times, 'not to overspring the gun', usually in feed problem discussions. After playing around with the feed process a good bit, it finally sunk in why, and that this is one of his most valuable nuggets. I wish more folks would take it to heart. He should tattoo it across the top of this site.

As to perceived recoil, well, that's a very slippery slope around here. Everyones' perception is different, and fits the old Supreme Court Justices' comment on pornography: " I can't define it, but I know it when I see (feel) it. "

What I do know is that there is nothing, short of changing the weight of the gun or the power of the load, that will change the amount of recoil that ultimately ends up in the hand.

[David Rose]

I'm hoping Tuner will chime in on this. I'm getting comments like, "you gotta be a hoss to work this one". That is with Wolff so called 16# springs and 23# hammer springs and STANDARD firing pin stops. They aren't hard for me to work, but I have good strength in my wrists. Wife also complains and she works the factory guns all day long. I'm stongly considering trimming back the 16# springs. If the factories can do it... Or do they not consider that the frames may get pounded?

David, the puzzled

[Iron bottom]

Was checking the prints I have (Nicolaus) and found the following information on the recoil spring

Load at compressed length of 3.72 inches= 8.00 lb + or - 0.50 lb

Load at compressed length of 1.81 inches= 13.55 lb + or - 0.60 lb

Spring rate= 2.88 lb/in REF

Solid length= 1.375 max

I've had about the same experience you've had with Colt and Wolff, David. The variation may be coming from the compressed length when the different spring rates are measured. Looks like an extra 1/2 inch, difference between 1.81 and 1.375, will add about another lb and a half. A fully compressed spring is in the neighborhood of 16 lbs. My math, of course.

[auto45]

I'm not sure on "felt recoil", because some people are "unfeeling" :D , but the heavier springs definitely dip your front sight(gun) down more coming back.

Maybe Colt uses "weaker" springs so it doesn't "out-run" the magazine, easier to rack, less "limp-wristing", etc, etc?
And they know, few people shoot enough rounds through it to even test the "pounding" of the frame.

I'll "defer" to Tuner. ;)

[David Rose]

That all could well be, Auto. Maybe Tuner will show up. I may have to "get" him to look at this.

David

I'm not sure on "felt recoil", because some people are "unfeeling" :D , but the heavier springs definitely dip your front sight(gun) down more coming back.

Maybe Colt uses "weaker" springs so it doesn't "out-run" the magazine, easier to rack, less "limp-wristing", etc, etc?
And they know, few people shoot enough rounds through it to even test the "pounding" of the frame.

I'll "defer" to Tuner. ;)

[1911Tuner]

Simple physics will provide the answer to this one...

Newton's 3rd Law of motion is in full effect when the subject is recoil springs and felt recoil.

First...Springs work in both directions. This is a fundamental truth whenever dealing with any force vector. Force forward equals force backward. Always.

When the slide moves backward, it compresses the spring. As the spring compresses, it also pushes forward on the slide with equal force. Because it uses the frame to push off of...it follows that it will push on the frame in the opposite direction...backward. The stronger the spring...the harder it pushes for a given amount of compression. Because the spring is a vector of force between the slide and frame...it acts on both equally.

Another point...Newton's 1st dictum:

Objects at rest tend to remain at rest. Mass resists accelerative forces by the square of the force applied. The harder and faster that you push on it...the harder it resists.
You can toss a baseball across the room almost without effort. If you want to make it break 100 mph like a big league pitcher...you have to use a [heckuva] lot more force on it.

Therefore...Higher-powered ammo will accelerate the slide harder and faster because of a higher force imposed. The faster slide will multiply the recoil spring's effect because it's being compressed faster. AND...because the spring also has mass...that has to be factored in as well. Remember...Force forward equals force backward. Whatever force is applied will create an equal force in the opposite direction.

[gbw]

gbw,

I found a couple of interesting things. Two Colts, one an 80 series, the other a 90, both NIB, had recoil springs that weighed 13# plus or minus 1/4. That lead me to not trust the spring scale. So I grabbed a target rifle off the wall, weighed it on a known accurate postal scale, and found the spring scale to be off less than 1/4# at about 13#. After the marker was reset slightly, the spring gauge gave 13# on one and 13 1/4 on the other Colt spring. The Wolff springs marked as 16# showed about 16 1/2#. So if the spring gauge is off, it is still showing considerable difference. Is Colt listening to Tuner?

Sorry if any of this is unclear. Writing in a rush at work.

David

This is real interesting, but not too surprising.

But, were all of the tested springs 'broken in'? IIRC, springs must be compressed several times when new to take their initial 'set', and to reach their nominal weights. After that, properly made springs tend to not change much over many thousands of compression cycles.

Second question is: assuming a broken in Wolff is 16# and the spec appears to call for 13-14, how much should be taken off a Wolff to reach this value?

Third is just a comment on 1911Tuners priceless pearl - don't overspring. We've all seen pistols that will cycle flawlessly when cycled by hand (even if it's done sharply) with no spring, yet become very rough or choke when a 16# or heavier spring is installed. To me, this would seem to indicate that stronger springs actually reduce reliability, which I believe has been Tuners' point all along?? How much increase in battering / cracking will occur when going from 16# to 14#? I'd love to know, but I don't. For range guns I don't care, as they all use buffs. For a 1911 carry pistol I would not use a buff.

[wichaka]

Been running 14-16lb springs on my full size and 16-17lb on my Commanders for years........'nary a problem.

They run very smooth............

[David Rose]

gbw,

These 16#ers were new from the package. I did compress them several times each during the weighing, but possibly not enough to break them in. And that could be why they weighed 1/2# heavy. The 13s were in handguns that get cycled at least once each time they are handled, which has been quite a few times. On the two guns that I just built, that feel heavy, they've been worked many dozens of times plus firing 200 rounds through one and around 75 through the other. I've not weighed those springs, but the action is way heavier than the new Colts.

I happened to notice that after testing, I mixed up a Colt spring and a Wolff and had to reweigh to get the correct one back in the gun. Laying next to each other, they were exactly the same length. Wire diameter difference was not apparent to the eye, and I didn't measure it, nor did I count coils. But both were almost fully compressed when pulled to the mark on the test gauge. However, I was focused on the gauge more than the spring when testing, so I could have missed a coil or two by eye. My point is, since the springs are the same length uncompressed, I'm not sure trimming coils would be the best way to lighten them.

I asked Tuner almost the same question about battering this afternoon. I haven't seen his reply yet, as he said it's been busy there. I agree on the buffs.

When you said, "...and the spec appears to call for 13 - 14#...", did you mean because that is what Colt seems to be using? Or do you have someone's spec that calls for that? Wasn't JMB's spec 16# only? Does Colt presently claim to use 16# springs? And did JMB's recoil spring spec change with changing from the small radius firing pin stop to the larger one for the military? Lots of questions...

Also, the locking/unlocking timing will probably be effected to some extent with the lighter spring.

David



This is real interesting, but not too surprising.

But, were all of the tested springs 'broken in'? IIRC, springs must be compressed several times when new to take their initial 'set', and to reach their nominal weights. After that, properly made springs tend to not change much over many thousands of compression cycles.

Second question is: assuming a broken in Wolff is 16# and the spec appears to call for 13-14, how much should be taken off a Wolff to reach this value?

Third is just a comment on 1911Tuners priceless pearl - don't overspring. We've all seen pistols that will cycle flawlessly when cycled by hand (even if it's done sharply) with no spring, yet become very rough or choke when a 16# or heavier spring is installed. To me, this would seem to indicate that stronger springs actually reduce reliability, which I believe has been Tuners' point all along?? How much increase in battering / cracking will occur when going from 16# to 14#? I'd love to know, but I don't. For range guns I don't care, as they all use buffs. For a 1911 carry pistol I would not use a buff.

[David Rose]

Wichaka,

Do you run full charge loads in the full size with 14lb springs?

David

Been running 14-16lb springs on my full size and 16-17lb on my Commanders for years........'nary a problem.

They run very smooth............

[1911Tuner]

Second question is: assuming a broken in Wolff is 16# and the spec appears to call for 13-14, how much should be taken off a Wolff to reach this value?

None. Wolff makes a spring in the range that you want. Better to use a long, light spring than a short heavy one.

How much increase in battering / cracking will occur when going from 16# to 14#? I'd love to know, but I don't. For range guns I don't care, as they all use buffs. For a 1911 carry pistol I would not use a buff.

Battering....or peening...will naturally increase. But it's not as much of an issue as you fear, assuming that all impacting surfaces are square to each other. Contrary to popular belief, cracking at the junction of spring tunnel and the forward ends of the frame rails isn't caused by this impact...though it's related. It's caused by insufficient clearance between the top edge of the tunnel and the bottom edge of the slide rail when the slide is full rearward. SInce the current demand is for a pistol that doesn't show any light through that area...I expect that it isn't gonna go away.

Also, the locking/unlocking timing will probably be effected to some extent with the lighter spring.

Nope. It's a commonly held belief that the spring controls barrel disengagement and drop timing. I refuse to say "Unlock" because the lugs lock under pressure. Once the
bullet is gone, the pressure is gone. The lugs disengage horizontally...and unlock.

"Timing" is often confused with "Time." While the slide will move faster with a lighter spring...the timing of the barrel disengagement will remain the same. Time is a function of speed and distance. Timing is mechanically fixed.

Think of it like this:

Assuming no automatic spark advance...If your car's ignition system fires the plug at 10 degrees BTC...it will fire at 10 degrees BTC regardless of the engine's RPMs...and the piston's speed.

[gbw]

gbw,

These 16#ers were new from the package. I did compress them several times each during the weighing, but possibly not enough to break them in. And that could be why they weighed 1/2# heavy. The 13s were in handguns that get cycled at least once each time they are handled, which has been quite a few times. On the two guns that I just built, that feel heavy, they've been worked many dozens of times plus firing 200 rounds through one and around 75 through the other. I've not weighed those springs, but the action is way heavier than the new Colts.

I happened to notice that after testing, I mixed up a Colt spring and a Wolff and had to reweigh to get the correct one back in the gun. Laying next to each other, they were exactly the same length. Wire diameter difference was not apparent to the eye, and I didn't measure it, nor did I count coils. But both were almost fully compressed when pulled to the mark on the test gauge. However, I was focused on the gauge more than the spring when testing, so I could have missed a coil or two by eye. My point is, since the springs are the same length uncompressed, I'm not sure trimming coils would be the best way to lighten them.

I asked Tuner almost the same question about battering this afternoon. I haven't seen his reply yet, as he said it's been busy there. I agree on the buffs.

When you said, "...and the spec appears to call for 13 - 14#...", did you mean because that is what Colt seems to be using? Or do you have someone's spec that calls for that? Wasn't JMB's spec 16# only? Does Colt presently claim to use 16# springs? And did JMB's recoil spring spec change with changing from the small radius firing pin stop to the larger one for the military? Lots of questions...

Also, the locking/unlocking timing will probably be effected to some extent with the lighter spring.

David

I'm not quite clear on Tuners' description of which lack of clearance causes cracking. Can anyone clarify a bit? What light are folk not wanting to see these days? I got slide fully to rear part, but I'm really unclear on the clearance mentioned.

The "specs" I'm talking about are largly emperical. Davids' measurement of the Colt NIB springs, others I've heard about with GI guns, I think Springfield guns are sprung between 13-14#, and so on.

Also Iron Bottoms post above showing some old Gov't specs seems to fall in the same arena.

[1911Tuner]

I'm not quite clear on Tuners' description of which lack of clearance causes cracking. Can anyone clarify a bit? What light are folk not wanting to see these days? I got slide fully to rear part, but I'm really unclear on the clearance mentioned.


Slide to the rear...completely...and against the spring guide flange. Slip a feeler gauge between the top edge of the spring tunnel and the bottom of the slide. You need a minimum of .007 inch there, and .010 is better.

The cross-section of the spring tunnel is thin. When the slide impacts the guide rod flange...and the frame...the tunnel flexes upward toward the impact. The front corner contacts the slide and because that point provides the maximum amount of leverage, it places a stress at the thin corner where the tunnel and frame rails meet. Sharp corners have stress risers in them. A very likely place for a crack to start.

Cut a very slight angle on the top of the spring tunnel...from the rails to the front. About one degree should be enough...and break the corner at the front. That will go a long way toward preventing or delaying a crack in that area.

While a buff will help...it only masks the cause instead of addressing the real problem.

[wichaka]

Wichaka,

Do you run full charge loads in the full size with 14lb springs?

David


Yes, when running my reloads and hardball. I also have them in my gun while on duty, loaded with +P stuff.
During our change over from old to new duty ammo, when we shoot it up, I'll put in a 16lb for the full size, and a 18lb for the Commander.

[Jolly Rogers]

[QUOTE=gbw]This is real interesting, but not too surprising.

Second question is: assuming a broken in Wolff is 16# and the spec appears to call for 13-14, how much should be taken off a Wolff to reach this value?
[QUOTE]
Based on my 30 years in the auto business doing suspension work...Shortening a spring makes it shorter and stronger not weaker.
A coil spring works on the same principal as a torsion spring. It has to wind and unwind to compress and extend. If one shortens a torsion spring it gets stiffer to twist. Hope I have been able to explain the situation as I understand it :) Tuner ...you understand physics well...does this make sense to you? JR

[gbw]

Shortening a coil spring will make it shorter of course, and weaker, not stronger. Shortening a straight torsion spring would be analogous to increasing the coil spacing in a coil spring (during manufacturing, not by stretching an already made spring), which we are not doing.

Also, remember that 1911 springs are captive at both ends and the length of travel is limited, extension and compression.

[RickB]

Cutting a coil spring increases the rate. An 18# Commander spring is merely a 16# Government spring with eight coils clipped off. I don't understand the physics of it, though.

[gbw]

Cutting a coil spring increases the rate. . .

It doesn't, that would require a metallurgical miracle of sorts. Commanders have shorter spring tunnels, so the pre-load is higher when the pistol is assembled, plus the compressed length is shorter - each coil is compressed further - closer to binding, so higher torsion resistance. But the compression rate per coil doesn't change.

As a test, assemble a slide, frame, barrel, bushing, slidestop and link and the recoil parts only. Start cutting coils off the recoil spring and note what happens to the force required to cycle the slide.

[David Rose]

Tuner, sorry about the "unlock" statement. ...old habit... I should have said unbreached. But if the slide is moving faster, as you say, then won't unbreaching occur faster? My thinking is that this could occur faster than the pressure drop, which will be at the same rate. We don't want to unbreach before pressure is where it should be. Are you saying that even with a reduced power spring, the pressure is gone before the movement is enough to unbreach? That I can understand. At what point does that cease to be the case? Or would that be so light as to not give effective stripping, feeding and slide return?

David

Nope. It's a commonly held belief that the spring controls barrel disengagement and drop timing. I refuse to say "Unlock" because the lugs lock under pressure. Once the
bullet is gone, the pressure is gone. The lugs disengage horizontally...and unlock.

"Timing" is often confused with "Time." While the slide will move faster with a lighter spring...the timing of the barrel disengagement will remain the same. Time is a function of speed and distance. Timing is mechanically fixed.

Think of it like this:

Assuming no automatic spark advance...If your car's ignition system fires the plug at 10 degrees BTC...it will fire at 10 degrees BTC regardless of the engine's RPMs...and the piston's speed.

[kel]

Tuner, sorry about the "unlock" statement. ...old habit... I should have said unbreached. But if the slide is moving faster, as you say, then won't unbreaching occur faster? My thinking is that this could occur faster than the pressure drop, which will be at the same rate. We don't want to unbreach before pressure is where it should be. Are you saying that even with a reduced power spring, the pressure is gone before the movement is enough to unbreach? That I can understand. At what point does that cease to be the case? Or would that be so light as to not give effective stripping, feeding and slide return?

David
The old yarn I have heard is that you can remove the recoil spring entirely and fire the gun safely. I can't recall the name of the gunsmith that did this to prove the point. Keep in mind that the gun is only in battery for a very short distance so the recoil spring is not completely compressed and thus not exerting its full force on the slide.

[David Rose]

Johnny, where do you get the .007 to .010 numbers? I haven't measured the gun I'm working on, but the finish I've applied will show contact immediately, and I have none. I did cut the top of the tunnel for clearance, but just barely with slide forward. There may be more when retracted, that I haven't noticed. And the verticle movement of this slide/frame is under .002. So maybe that is the reason for no contact? I'll have to try your measurement.

David

Slide to the rear...completely...and against the spring guide flange. Slip a feeler gauge between the top edge of the spring tunnel and the bottom of the slide. You need a minimum of .007 inch there, and .010 is better.

The cross-section of the spring tunnel is thin. When the slide impacts the guide rod flange...and the frame...the tunnel flexes upward toward the impact. The front corner contacts the slide and because that point provides the maximum amount of leverage, it places a stress at the thin corner where the tunnel and frame rails meet. Sharp corners have stress risers in them. A very likely place for a crack to start.

Cut a very slight angle on the top of the spring tunnel...from the rails to the front. About one degree should be enough...and break the corner at the front. That will go a long way toward preventing or delaying a crack in that area.

While a buff will help...it only masks the cause instead of addressing the real problem.

[David Rose]

Good point, kel! Thanks. At that point there would be very little pressure from the spring. With the Colts that I've weighed, I'll bet it would be less than a pound or two. The 16 pound springs have probably 5 pounds of pressure or more at this less compressed point. So that can't matter much.

David

The old yarn I have heard is that you can remove the recoil spring entirely and fire the gun safely. I can't recall the name of the gunsmith that did this to prove the point. Keep in mind that the gun is only in battery for a very short distance so the recoil spring is not completely compressed and thus not exerting its full force on the slide.

[MedSpec65]

I switched my Kimber Custom II spring from the NIB 16 Lb to the 18.5 Lb Wolff because of numerous loading and ejection failures with white box 230 gr ball ammo. This, and McCormick mags have solved the problem. I haven't noticed any sharper recoil.

[David Rose]

The Wolff 14# recoil springs are $5.26 each vs $2.15 for the 16# in bulk packs. That does add a new factor into the equation. Maybe trimming is in order as suggested...

David

[kel]

I switched my Kimber Custom II spring from the NIB 16 Lb to the 18.5 Lb Wolff because of numerous loading and ejection failures with white box 230 gr ball ammo. This, and McCormick mags have solved the problem. I haven't noticed any sharper recoil.
Solved the problem or eliminated the symptom?

[1911Tuner]

Kel. That was Ned Christiansen who fired one without the recoil spring...repeatedly.

David...The clearance specs came from a Navy armorer who started learnin' the trade before WW2 cut loose...sometime in the mid-30s. Apparently, the information was good, because I've got a couple of beaters that have never worn a buff...have seen something approaching 300,000 rounds betwixt'em...and neither one has a crack in that area.

[RickB]

It doesn't, that would require a metallurgical miracle of sorts. Commanders have shorter spring tunnels, so the pre-load is higher when the pistol is assembled, plus the compressed length is shorter - each coil is compressed further - closer to binding, so higher torsion resistance. But the compression rate per coil doesn't change.


OK; cutting a 16# GM spring, and then mounting it in a Commander creates an effective rate of 18#? How's that? The "18#" spring in a Commander IS a 16# GM spring that's been cut.

[1911Tuner]

OK; cutting a 16# GM spring, and then mounting it in a Commander creates an effective rate of 18#?

More like about 17 at full compression as installed in the gun...depending on how many coils you leave...which is a gracious plenty.

[David Rose]

I think I get it. The slide does compress the spring farther in the Commander, doesn't it?

David

More like about 17 at full compression as installed in the gun...depending on how many coils you leave...which is a gracious plenty.

[1911Tuner]

The slide does compress the spring farther in the Commander, doesn't it?

Yep. This probably fits into the "More has been forgotten" category. I had a leg up. The men who mentored me were two of those people who had forgotten more than most will know.

[gbw]

David, I have a photo ready for in the am on Tuners' measurements to be sure I've got them right - at least I hope I do. I want to be sure I understand them.

I measured a 14# and 16# spring. The difference is either .002 or .0015 in wire dia. Hardly seems worth the price difference! I guess it's just demand and volume. Anyow, I'm gonna get more 14s.

Johnny - thanks! Also, I've got 20 of the CM mags ordered, hybrid 7-rd, 10 carbon, 10 stainless on the group order, very anxious to try them out and report to your survey.

[David Rose]

gbw, I'm not sure what you mean about the photo, but I'll wait and see. :) Thanks for checking wire diameter. I thought that might be the case. But I am puzzled by the cost difference. You bet it is supply and demand, but... If most of the gun makers are using 13 or 14 pound springs, where are they getting them? Long ago I was told that Wolff manufactered almost all the small springs made in this country. Maybe we should price springs from the manufacturers before buying Wolff. Colt is $4.57 instead of $5.26 for the Wolff.? This is dealer on both. Also, in Wolff, standard and progressive springs are the same price, which also seems odd. But no bulk prices on either. <grrrr> If you find any less expensive 14#ers that we can count on the quality, let me know. I just got in 10 of the 16s and now I'm going to recommend 14s. <sigh> Such is the life of the everyday gunsmith... ;-) Sure as heck, we order the Colts and they will come in as 16# springs, and we have no reason for complaint.

David



David, I have a photo ready for in the am on Tuners' measurements to be sure I've got them right - at least I hope I do. I want to be sure I understand them.

I measured a 14# and 16# spring. The difference is either .002 or .0015 in wire dia. Hardly seems worth the price difference! I guess it's just demand and volume. Anyow, I'm gonna get more 14s.

Johnny - thanks! Also, I've got 20 of the CM mags ordered, hybrid 7-rd, 10 carbon, 10 stainless on the group order, very anxious to try them out and report to your survey.

[gbw]

The photo is to be sure I (may others also) understand the exact areas we are talking about. Sometimes I get confused.

The clearance marked .002 on this gun is, I believe, the area where the clearance should be .007 - .010"?

The 1 degree angle cut is marked along the tunnel (very exaggerated), but is that correct?

Would it be acceptable to relieve the bottom of the slide rails parallel to A-B (also exaggerated) to get the same clearance?

Thanks again!

http://i113.photobucket.com/albums/n240/gbw_jr01/RecoilTunnel.jpg

[Sniper350]

The front corner contacts the slide and because that point provides the maximum amount of leverage, it places a stress at the thin corner where the tunnel and frame rails meet. Sharp corners have stress risers in them. A very likely place for a crack to start.

1911Tuner -- could you explain a little more in detail about what you meant about "stress risers"

Thanks !

JF.

[1911Tuner]

could you explain a little more in detail about what you meant about "stress risers"

http://en.wikipedia.org/wiki/Stress_concentration

[gbw]

I'll give it a shot, but someone can probably do better:

Stress Risers. I'm betting you know this instinctively. It is a property of solid materials, especially metal.

For nearly any shape, any sharp interior angle (a sharp corner, a crack, a nick) will tend to accumulate stresses placed on that shape at the junction nearest the applied stress. The sharper the corner, the more pronounced is the likelihood that the part will fail at the bottom 'v' of the corner. The corner, crack, nick, or a any 'v' shaped cut is called a stress riser for that reason.

For example, if you cut a 'v' notch in a piece of plate steel and attempt to pull it apart, it will always separate at the 'v' of the notch, even if the plate is thicker at the base of the 'v'.

That's the reason that airplane and ship port holes and door corners are not square. They learned the hard way not to use square corners (stress risers) in holes through structural (stressed) pieces.

The effect can be mitigated by reinforcement, if it's designed correctly to spread the stress.

In a 1911, the very sharp interior corner where the dust cover / spring tunnel joins the rest of the frame, forming the shoulder where the recoil spring flange sits, is a stress riser. When frames crack the crack very often starts on top of the dust cover at the junction formed by that corner

[Sniper350]

Thank you 1911Tuner ............ and Thank you GBW

Very nicely explained to where even I can understand it :)

I am wondering if that's why SIG left those square blobs at the ends of the rails & dust cover on their GSR Slides ??? Maybe trying to mitigate a "stress riser" situation.

The only problem being, on my Slide ....those raised areas of metal battered my guide rod flange into oblivion. They acted like little ball peen hammers ........ peening away at the guide rod flange until it was bent and contacting the sides of the Slide. I have seen other older GSR's that had the same Slide treatment, so I don't think mine was a forgotten defect or missed de-burring.??

I would call SIG ........... but I don't think I would get the "real" purpose out of them anyway.

JF.

[gbw]

You're welcome.

Now I hope 1911Tuner and David Rose will comment on the pic above. I'd like to be sure that I understand where the clearances Tuner speak of are located.

[David Rose]

That is what I understood Tuner to say. Most of the fitters that I've read, say to have clearance there. He'll probably have time to get back to it in a bit. I just didn't realize it needed to be that much. That section of the slide should not effect the fit of slide to frame when the slide is forward, should it? So I suppose you could fit the slide rather than the frame. But the frame is totally exposed when disassembled. A plain flat file could do the job with only reasonable care. Working those rails would be much tougher, it seems to me. Especially so if we need that .007 clearance. Besides, the slide is harder than the frame.

David

You're welcome.

Now I hope 1911Tuner and David Rose will comment on the pic above. I'd like to be sure that I understand where the clearances Tuner speak of are located.

[MedSpec65]

Solved the problem or eliminated the symptom?After 500+ rounds downrange with no failures, the symptoms have definitely been eliminated. Unless you're suggesting Kimbers are fatally flawed pistols, I would have to say the problem has been solved as well.

[David Rose]

Med, I think the reference was just to the fact that the heavier spring will strip rounds "harder" from the mag. This will often mask the actual cause(s).
Since, as noted, it is somewhat harder on the gun, it usually isn't the best cure for most problems, though it may mask them.

David

After 500+ rounds downrange with no failures, the symptoms have definitely been eliminated. Unless you're suggesting Kimbers are fatally flawed pistols, I would have to say the problem has been solved as well.

[gbw]

That is what I understood Tuner to say. Most of the fitters that I've read, say to have clearance there. He'll probably have time to get back to it in a bit. I just didn't realize it needed to be that much. That section of the slide should not effect the fit of slide to frame when the slide is forward, should it? So I suppose you could fit the slide rather than the frame. But the frame is totally exposed when disassembled. A plain flat file could do the job with only reasonable care. Working those rails would be much tougher, it seems to me. Especially so if we need that .007 clearance. Besides, the slide is harder than the frame.

David

Hmmm.....you're right. Thanks.

[MedSpec65]

Med, I think the reference was just to the fact that the heavier spring will strip rounds "harder" from the mag. This will often mask the actual cause(s).
Since, as noted, it is somewhat harder on the gun, it usually isn't the best cure for most problems, though it may mask them.

DavidThanks for clarifying your reference David. I switched to the 18 Lb spring because of advice from a rangemaster when I was having ejection and feed failures. His opinion was the heavier spring should be used with heavier loads, such as the 230 gr ball ammo we commonly use for practice. In retrospect, I think the Kimber magazines were the real culprit. I'm going to take the advice illustrated here and mitigate the stress on the frame by re-installing the 16 Lb factory specified spring.

[kel]

After 500+ rounds downrange with no failures, the symptoms have definitely been eliminated. Unless you're suggesting Kimbers are fatally flawed pistols, I would have to say the problem has been solved as well.
I am not saying anything about Kimber pistols, just that switching to a heavier spring is not a fix because it should work with a 16 pound spring. Correcting what prevents it from doing so would be a better fix. It beats knowing that the gun is running on the edge of reliability with only two pounds of spring between you and trouble.