Loose slide to frame fit?
- Thread starter LarryE
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1911Tuner
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Peen
Hi Larry, and welcome aboard.
Peening and swaging drive the frame rails down and close up the ways that the slide rails ride in. It's done to reduce or eliminate vertical play in the slide, and on occasion to bring the slide lower on the frame to bring the slide installed height into spec. Two different operations with different techniques...but the peening is the same in both.
Basically, the smith uses either a small ball-peen hammer to tap the rails down, or a swaging punch and a larger hammer...which works very well for closing up the ways. I've done it both ways, and there are advantages and disadvantages with either. How badly worn or mismatched the dimensions dictates which method that I use...and sometimes I use both on the same gun. First peening, and initial fitting...followed by light swaging and final fitting.
It's a fairly time-consuming exercise unless the pistol needs only light adjustment....003-.005 inch or so. Often, a gun that's not badly worn will require tightening in the front only, if the rear play is within acceptable limits.
For a simple tightening operation, the rail dimension of the slide is taken by measuring from a plate that fits into the ways to the bottom edge of the rails, and a guide bar set is selected that closely matches that dimension.
Some like to pick a set that stops the peening at .001 inch over slide rail size...and others like to go with one that's the same size or even a little smaller to allow for truing with a file and a hand-lapped finish fit. If you're good with a file, you can often bring the dimensions in close enough to hand-lap with oil. I normally need to use straight J&B Bore Cleaner, followed with 500 or so hand-cycles with plenty of fine oil.
Swaging is normally done on the ends of the rails only...about an inch or so from the ends...and the thin, center section left alone.
Hi Larry, and welcome aboard.
Peening and swaging drive the frame rails down and close up the ways that the slide rails ride in. It's done to reduce or eliminate vertical play in the slide, and on occasion to bring the slide lower on the frame to bring the slide installed height into spec. Two different operations with different techniques...but the peening is the same in both.
Basically, the smith uses either a small ball-peen hammer to tap the rails down, or a swaging punch and a larger hammer...which works very well for closing up the ways. I've done it both ways, and there are advantages and disadvantages with either. How badly worn or mismatched the dimensions dictates which method that I use...and sometimes I use both on the same gun. First peening, and initial fitting...followed by light swaging and final fitting.
It's a fairly time-consuming exercise unless the pistol needs only light adjustment....003-.005 inch or so. Often, a gun that's not badly worn will require tightening in the front only, if the rear play is within acceptable limits.
For a simple tightening operation, the rail dimension of the slide is taken by measuring from a plate that fits into the ways to the bottom edge of the rails, and a guide bar set is selected that closely matches that dimension.
Some like to pick a set that stops the peening at .001 inch over slide rail size...and others like to go with one that's the same size or even a little smaller to allow for truing with a file and a hand-lapped finish fit. If you're good with a file, you can often bring the dimensions in close enough to hand-lap with oil. I normally need to use straight J&B Bore Cleaner, followed with 500 or so hand-cycles with plenty of fine oil.
Swaging is normally done on the ends of the rails only...about an inch or so from the ends...and the thin, center section left alone.
JackOfAllTradesMasterAtNone
Member
OK Tuner.. More.
Peening assists in taking up slop and is used to pull the slide tighter 'vertically'.
What about horizontally? Is this where squeezing the slide comes into play? Can you expand on why, how, and if the two, peening and squeezing, processes are ever combined to make a slide fit a frame in a uniform tightness throughout it's full motion?
My Colts rattle. They're not as accurate as I know they could be. But they function very well. My Kimber is very tight. It's also very accurate off hand, (I must get it in my friends Ransom rest soon). Still, it seems to funtion very reliably too. A local Clark/Colt isn't near as tight as my Kimber, hits the 10 ring, (with many X's), from the Ransom rest on every shot. (50yd). -Other than crisp trigger, a match grade barrel, How much does the slide fit play into how accurate a pistol is? All of the moving pieces/tollerance factor to a certain degree, but which has the most value?
-Steve
Peening assists in taking up slop and is used to pull the slide tighter 'vertically'.
What about horizontally? Is this where squeezing the slide comes into play? Can you expand on why, how, and if the two, peening and squeezing, processes are ever combined to make a slide fit a frame in a uniform tightness throughout it's full motion?
My Colts rattle. They're not as accurate as I know they could be. But they function very well. My Kimber is very tight. It's also very accurate off hand, (I must get it in my friends Ransom rest soon). Still, it seems to funtion very reliably too. A local Clark/Colt isn't near as tight as my Kimber, hits the 10 ring, (with many X's), from the Ransom rest on every shot. (50yd). -Other than crisp trigger, a match grade barrel, How much does the slide fit play into how accurate a pistol is? All of the moving pieces/tollerance factor to a certain degree, but which has the most value?
-Steve
When peening, where is the hammer hitting at? 45 degrees on the corner to push the rail edge down only or hitting straight on the top to drive the top surface down?
How do you measure "play"? I clamp the frame on a vise and attach dial indicator to the vise to measure the vertical play on my HiPower slide and it has 0.005" play when measured at the front of rear sight. I could slip a 0.009" shim gage between the slide and frame at the worst location. Is this much play considered normal? I am not talking about a target gun, just punching papers at the range, but the play is annoying. Thanks.
Hank
How do you measure "play"? I clamp the frame on a vise and attach dial indicator to the vise to measure the vertical play on my HiPower slide and it has 0.005" play when measured at the front of rear sight. I could slip a 0.009" shim gage between the slide and frame at the worst location. Is this much play considered normal? I am not talking about a target gun, just punching papers at the range, but the play is annoying. Thanks.
Hank
1911Tuner
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Howdy Jack.
Yes. Both operations are often done together.
Tightening the sideplay can done by squeezing the slide, but it's a tricky operation that can break a slide if over-squeezed and/or taken too far.
Also, the older slides weren't hardened throughout, and would tolerate it better than newer slides. There's a technique that's a little too involved to outline here, but basically is done with shims of increasing thickness in order to sneak up on the final amount. For hard slides, I also like to heat them in an oven beforehand. About 250-300 degrees should do...and you still run the risk of hearing that dreaded "tink" that lets you know you've just turned your slide into a paperweight. I don't like to squeeze slides if there's any way around it.
Some smiths...on some guns...weld the frame rails and recut to fit the slide...if the rails are worn to the point that too much slide work would be required. That's very much old-school these days though, and rarely done any more. More time and cost effective to reject the frame or slide and start with new components that are plentiful and reasonably-priced.
The horizontal fit isn't as critical as the vertical...either for accuracy or functional reliability... (No Virginia. Rattletrap loose doesn't insure reliability.
Beyond a certain point, it can be detrimental.)...but it does have a definite effect. For a general-purpose, go anywhere/do anything 1911...Kuhnhausen refers to it as a "Rough and Tumble" gun, about .005 inch in both planes is good enough. I like to see .003 to .005 as a good balance between dirt/neglect tolerance and accuracy. Accuracy is more closely determined by barrel fit anyway...and the group difference between .003 inch clearqnce and .001 inch...or match-grade fit...would require a Distinguished Expert or Grand Master to see the difference, and unless the barrel is carefully fitted,
even that class of shooter ptobably couldn't tell.
Hank,
If the 009 gauge slips into the gap with a .005 inch indicated vertical play, it's likely that it's at the dust cover...and probably due to the fact that the dust cover is slightly angled toward the front. This si done to prevent cracking at the junction of dust cover and rails...in the corner where a stress riser or three probably exist. Many folks don't realize that when the slide hits the frame in full recoil, the dust cover flexes upward slightly. The clearance is there to prevent contact between the top of the cover and the slide rail...which would stress the thin cross-section and start a crack if the contact was very hard.
Another point is that...a gun that is fitted with .003 inch will be barely discernible when the rails are dry...and when oiled, the gun will usually
seem to be fitted with zero play. You'd have to pull hard and watch closely to be able to see it.
On peening and swaging...the rails should be swaged as straight down as possible. The punches are designed to do that. Peening compresses the steel some, and usually brings the rails down on a slight angle. Straight down is the best and longest-lasting method, and whenever I do peen, I usually clean up the tops by draw-filing and follow by swaging for the final fit.
Be aware that when you do either, you lower the whole top-end of the gun...which may require adjustment to the disconnect's timing slot. If the rails are peened and swaged...and draw-filed to clean the marks, you may also have to refit a new ejector, since it often creates clearance between the bottom of the ejector and the top of the frame.
Howdy Jack.
Yes. Both operations are often done together.
Tightening the sideplay can done by squeezing the slide, but it's a tricky operation that can break a slide if over-squeezed and/or taken too far.
Also, the older slides weren't hardened throughout, and would tolerate it better than newer slides. There's a technique that's a little too involved to outline here, but basically is done with shims of increasing thickness in order to sneak up on the final amount. For hard slides, I also like to heat them in an oven beforehand. About 250-300 degrees should do...and you still run the risk of hearing that dreaded "tink" that lets you know you've just turned your slide into a paperweight. I don't like to squeeze slides if there's any way around it.
Some smiths...on some guns...weld the frame rails and recut to fit the slide...if the rails are worn to the point that too much slide work would be required. That's very much old-school these days though, and rarely done any more. More time and cost effective to reject the frame or slide and start with new components that are plentiful and reasonably-priced.
The horizontal fit isn't as critical as the vertical...either for accuracy or functional reliability... (No Virginia. Rattletrap loose doesn't insure reliability.
Beyond a certain point, it can be detrimental.)...but it does have a definite effect. For a general-purpose, go anywhere/do anything 1911...Kuhnhausen refers to it as a "Rough and Tumble" gun, about .005 inch in both planes is good enough. I like to see .003 to .005 as a good balance between dirt/neglect tolerance and accuracy. Accuracy is more closely determined by barrel fit anyway...and the group difference between .003 inch clearqnce and .001 inch...or match-grade fit...would require a Distinguished Expert or Grand Master to see the difference, and unless the barrel is carefully fitted,
even that class of shooter ptobably couldn't tell.
Hank,
If the 009 gauge slips into the gap with a .005 inch indicated vertical play, it's likely that it's at the dust cover...and probably due to the fact that the dust cover is slightly angled toward the front. This si done to prevent cracking at the junction of dust cover and rails...in the corner where a stress riser or three probably exist. Many folks don't realize that when the slide hits the frame in full recoil, the dust cover flexes upward slightly. The clearance is there to prevent contact between the top of the cover and the slide rail...which would stress the thin cross-section and start a crack if the contact was very hard.
Another point is that...a gun that is fitted with .003 inch will be barely discernible when the rails are dry...and when oiled, the gun will usually
seem to be fitted with zero play. You'd have to pull hard and watch closely to be able to see it.
On peening and swaging...the rails should be swaged as straight down as possible. The punches are designed to do that. Peening compresses the steel some, and usually brings the rails down on a slight angle. Straight down is the best and longest-lasting method, and whenever I do peen, I usually clean up the tops by draw-filing and follow by swaging for the final fit.
Be aware that when you do either, you lower the whole top-end of the gun...which may require adjustment to the disconnect's timing slot. If the rails are peened and swaged...and draw-filed to clean the marks, you may also have to refit a new ejector, since it often creates clearance between the bottom of the ejector and the top of the frame.
Thanks, 1911 Tuner
Thanks, 1911 Tuner, I knew by reading your other posts that I would get a thorough and understandable explanation. Although I’ll never attempt the process, if I ever go to a pistolsmith, I’ll be educated about what is going on. Great folks and great information on this forum. Thanks again, Larry
Thanks, 1911 Tuner, I knew by reading your other posts that I would get a thorough and understandable explanation. Although I’ll never attempt the process, if I ever go to a pistolsmith, I’ll be educated about what is going on. Great folks and great information on this forum. Thanks again, Larry
JackOfAllTradesMasterAtNone
Member
Also many thanx Tuner. I appreciate your explanations very much. In my experience, most smiths of any particular tallent are willing to elaborate on the details of thier craft. You are a credit to your trade.
-Steve
-Steve
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