Revolver Action Job Question

[tomcatt51]

Hand thickness is pot luck. "Std" thickness hands seem to vary from .092" to .095".

Yes, it's still a valid test. Have another L frame you can "steal" the hand from to try?

 

[Pdxrealtor]

Great.

Yes, I have other L frames.

I just read the shop manuals section on long ratchets. I get what would cause the heavier trigger pull/slow return, but I am completely confused as to how the same cylinder and hand would work with a bit more cylinder end shake (different yoke) but still be the primary issue.

The issue of the long ratchets causing the heavier trigger pull, is an issue of the hand binding on the right hand side of the window.

The two seem to be completely separate issues. What the heck am I missing here?

 

[Pdxrealtor]

I know I am a bit late to this party, but the symptoms you are describing are exactly those which I get with a bent extractor rod.

The tolerance is that it must not be out of round (runout) exceeding .002 inches. I cannot perceive that small amount with my old, tired eyes without help, so I use the Power Custom Fixture to put the cylinder with attached extractor rod into the fixture, then spin the cylinder and observe the precision dial indicator to see if and where the runout is excessive, then bend it back into place. I can actually observe the excessive runout, but only if I place the extractor rod over a thin-lined piece of paper, line it up precisely, then spin the cylinder. Without the line for a reference point, I just cannot perceive runout of .002 inches.

My suggestion: reconfirm that the extractor rod is not bent.

appreciate the input

The same cylinder, extractor rod, hand and ratchets all work fine with a different yoke that puts cylinder end shake gaps just .001 looser than the guns original yoke.

 

[Pdxrealtor]

This is a 586 L comp revolver made in January 2015. I bought it used. There was obvious signs of tampering when I got it. But, how in the heck does the yoke end play get to .008?

That's the problem. Confirmed with trigger pull gauges both manual and digital Lyman. If I leave the .008 feeler gauge in there during the pulls I get +/- 3 ounces on the Lyman digital.

 

[ImprovedModel56Fan]

OK. I see why you want to really fix it. I'll stop the grease comments.

 

[armorer951]

While you're at it check and shim (if required) the yoke endshake also. Powers also has shims for the yoke. You check yoke endshake with the yoke sideplate screw removed.

Questions concerning checking for yoke end play after removing the yoke screw...... isn't the spring loaded yoke screw designed to mitigate the end play problem in the yoke stem? If the yoke is shimmed forward, how would you then resolve the resulting reduction in the B/C gap.

 

[Pdxrealtor]

Curious to hear the answer as well.

While shimming the yoke forward solves the problem I'm wondering if can accomplish the same thing by continuing to remove material from the yoke face.

When the yoke is not shimmed forward it positions the yoke back far enough that closing the cylinder removes all play in the cylinder on the yoke. Pushing the yoke forward while the cylinder is closed is not hard, but for lack of a better word it's not 'rattle' loose. It does take a bit of effort to push forward.

Adding dykem to the cylinder bearing shows that is where the friction occurs. It also lines up with the cylinders that show more resistance, and last it matches with wear marks on the frame.

The manual does mention shimming the yoke if you are dealing with the new style yoke retaining system, but I could not find where it describes how to check for yoke end play. Screw in or screw out.

When the cylinder is closed the back recoil plate pushes against the cylinder bearing and the cylinder runs out of room to move forward relieving the pressure on the cylinder bearing due to the yoke barrel being too long, .

Proper way to solve it?

1) I have room on the front of the yoke to shave more off the end of the yoke barrel allowing the cylinder to move forward?

2) Shim the yoke?

3) stone the cylinder bearing? I don't think so. But, it should work.

1 and 2 accomplishes the same thing with different methods.

Suggestions?

I keep going back to shimming the yoke because my other late model L frames don't have the movement in the yoke like this one.

I did try putting a different yoke retaining screw in with no change.

 

[Pdxrealtor]

The shop manual really should say something about the fact the yoke will slide forward while pushing on the cylinder to check cylinder end play. It should also discuss proper methods for testing the yoke play on the newer yokes.

The solution was simple once I quit thinking so hard (I actually just got sidetracked by Tomcatts suggestion to check the yoke end play).

The yoke barrel face had to be shaved. Plain and simple. Problem solved. I took off about .001 to .0015.

I'm very curious to hear how one determines if the yoke has end play that NEEDS to be corrected with shims (newer yokes of course). The cylinder retaining screw, as Armorer mentioned, mitigates the yoke end shake. You can check it all day without the screw and sure it will move in and out. But with the screw in, it doesn't move in and out unless you push forward with some effort.

Again, the shop manual mentions nothing about this.

So to sum it up for the next guy who may not have extra L frames laying around. Everything pointed to a ratchet and hand problem, even the troubleshooting section in the manual. 2-3 cylinders showed a higher resistance during trigger pulls.

The shop manual, while it talks a lot about fixing excessive end shake, did not mention anything at all about the possibility the yoke barrel face could be too long allowing such little end shake that a slight high portion of the cylinder bearing (or recoil plate) may cause a problem. This is easy to verify by looking at the recoil plate, or putting dykem on the cylinder bearing and going for a 'spin'.

In my case I have an obvious high spot in that location, but did not have the clearance (too little end shake).

Another clue would be the cylinder does not budge at all with light pressure front to back (I mean it's solid) when it's in the closed position.

I learned a lot on this one.

Looking forward to final input from armorer, tomcatt, and others. Thanks everyone who contributed.

 

[regalsc]

This long involved & expensive? problem & fix is why if I have a problem with a revolver it goes back to S&W then comes back in 2 weeks fixed for free.

 

[BUFF]

I believe that the OP was doing this because he wanted to learn and was enjoying the process, not to save time, money or aggravation.

 

[regalsc]

I believe that the OP was doing this because he wanted to learn and was enjoying the process, not to save time, money or aggravation.

I forgot to mention that I'm not handy enough to even consider attempting a project like that the reason they get sent back also.

 

[armorer951]

I believe the reason the problem of end shake on the "redesigned" yoke stem is not mentioned in the Kuhnhausen Shop Manual is because the spring-loaded screw holds the yoke in the proper position arbitrarily and without adjustment. As long as the spring loaded screw is in-tact and in place, there is in fact, no end shake on the yoke.

This new system is unlike the yokes in the older models which are held in proper position by a yoke screw with a solid stem which interfaces with the yoke button on the yoke stem. This button is hand fit to the screw. The yoke button can become worn, damaged from mishandling, or "peened" by recoil, making function checking and re-adjustment necessary. Using the "wrong" sideplate screw can also result in both gauge and functionality problems.

This new interface solved at least two problems....the button and screw no longer have to be hand fit, and, identifying the proper screw to use in the "yoke" position and keeping it separate from the other sideplate screws is now a moot point, since the screw in the new system is a different size and design.

 

[tomcatt51]

Questions concerning checking for yoke end play after removing the yoke screw...... isn't the spring loaded yoke screw designed to mitigate the end play problem in the yoke stem? If the yoke is shimmed forward, how would you then resolve the resulting reduction in the B/C gap.

The spring loaded plunger does a good job of hiding a poorly fitted yoke. When you fire the gun do you think the yoke doesn't overcome the spring/plunger and slam into the frame?

Set (shim) the yoke endshake (with the screw removed) so the yoke sits in contact with the frame like it should, them set (shim) the cylinder endshake. All is now as it should be...

 

[tomcatt51]

This new system is unlike the yokes in the older models which are held in proper position by a yoke screw with a solid stem which interfaces with the yoke button on the yoke stem. This button is hand fit to the screw. The yoke button can become worn, damaged from mishandling, or "peened" by recoil, making function checking and re-adjustment necessary.

On the "old design" (and the "new design" with the spring loaded plunger) the yoke is a "select fit" at the factory and when closed, no screw installed, it should sit "forward" against the frame and have no endshake. The only way to adjust the endshake once we get the gun is to add shims.

The screw and button (old design) and the spring and plunger (new design) both only hold the yoke in place when it's open.

This is a can of worms because of the peculiar way the Kuhnhausen book was edited. It made it seem you adjusted the (old design) yoke closed endshake by peening the button and fitting the screw. This is incorrect and a short lived fix as the button just gets dented by the screw until the yoke once again sits forward against the frame. Only works good for safe queens that are never fired.

Hope this helps.

 

[armorer951]

On the "old design" (and the "new design" with the spring loaded plunger) the yoke is a "select fit" at the factory and when closed, no screw installed it should sit against the frame and have no endshake. The only way to adjust the endshake once we get the gun is to add shims.

Endshake on the yoke is not remedied by pushing the yoke forward with shims to the point of contact with the frame. Shims are used as an "alternative" to peening the older design yoke button, because the shimming procedure is easier than hand fitting. (peening) Both peening and shimming serve to restore proper interface/contact between the yoke button and the yoke screw of the old design, and to hold the yoke back when the cylinder assy is closed.... thereby eliminating end shake (front to back movement) on the yoke stem. This properly maintained condition between the yoke and screw also prevents the front of the cylinder from contacting the barrel breech when the cylinder is closed.

However, with respect to the new spring loaded yoke screw, because this necessary maintenance of proper gauge is accomplished by the spring loaded plunger in the yoke screw, shimming should not be necessary, and peening is verboten.

If a condition of "yoke to frame" contact was used to fix the yoke in proper position when closed, and yokes were "select fit" to frame contact when first assembled, the only purpose for the yoke button and screw would be to prevent the cylinder from falling out of the gun when the cyl assy was opened, and preventing contact with the breech of the barrel when closing.


Clearly, because of frame to yoke tolerances and small size differences, all frame and yoke assemblies, even the new ones, are dependent on the yoke screw to maintain proper gauge, especially when the assembly is fully closed.

 

[tomcatt51]

I guess we're gonna disagree here. The yoke should sit forward against the frame. The yoke screw (old or new design) holds the yoke in position when it's open, minimizes "yoke open" endshake.

Yoke closed endshake is supposed to be achieved by "select fitting" the yoke at the factory. That "select fitting" is why yokes are "factory fit only". Note that even "new design" yokes with the spring and plunger are "factory fit only". After it leaves the factory our recourse is shims.

The problem with setting yoke closed endshake by peening the button is that after some rds are fired the screw will have beat a dent in the button and the yoke will have endshake again (also increasing cylinder endshake), the yoke being (again) able to move forward against the frame.

Those surfaces where the yoke and frame contact with the yoke forward are thrust surfaces, they're there for the yoke to sit against. Less endshake equals less pounding as the cylinder and yoke don't "get a run" at the surfaces. It's a much bigger surface than the sideplate screw contacting the button.

My SOP is to check yoke endshake and shim as required, then set cylinder endshake. Even on new guns I trim the yoke to accept cylinder endshake shims because they make a great bearing surface to keep the end of the yoke from cutting a groove in the bottom of its' bore in the cylinder.

For many shooters much of this doesn't matter, they don't put enough rds thru their guns. For those of us that shoot competitively and/or put a lot of rds thru our guns it makes a big difference in the gun staying in tolerance.

 

[armorer951]

We can agree to disagree.

I haven't been to the factory floor for several years, but I don't think assemblers have the time to "select fit" yokes based on yoke to frame contact. If that were the case, S&W wouldn't be teaching students how to repair yoke end shake at the armorer's school, and we wouldn't be having this "conversation".

Regardless whether or not the "yoke should sit forward against the frame", it doesn't in most cases. In those cases, it's necessary to remedy forward yoke battering and it's inevitable movement forward by intervention. The latest intervention, or invention, by S&W to help prevent or at least mitigate this inevitable forward movement is the spring loaded plunger in the yoke screw, and it's redesigned interface on the yoke stem. This design holds the yoke fully back throughout it's rotation in and out of the frame.

You have in this particular gun, which I believe he said was produced in 2015, what the OP described as .008" of yoke end shake when the yoke screw on the gun was removed. What happens when you shim the yoke forward to the idyllic point where it just contacts the frame?

In this case, the front gauge would then close by .008", and the rear gauge would open the same. This would result in the gun not only out of spec. both in front(B/C) and at the rear (headspace) of the cylinder, but probably unusable. To restore function, it would be necessary to install additional shims at the end of the yoke barrel to force the cylinder back to the place where correct tolerances were achieved.
"Creating" this arbitrary frame to yoke contact fitment on a factory fit frame and yoke will require shims. Sometimes, it will require lots and lots of shims, depending on how the parts were originall fit by the assembler.

 

[Pdxrealtor]

I understand what both of you are saying.

To be clear, the manual does explain how to correct YOKE end shake on the newer models with the spring loaded screw. The only solution offered due to the screw is shims. Peening is not recommended.

What the manual does not mention is how to properly check the newer model.

In any event... I'm going to keep this thread going since it's titled accordingly and this gun, a 2015 586 L comp, is going to be a 'race' gun for fun.

I will be ordering yoke shims, cylinder shims, the hammer boss/trigger boss tool and the sleeve that goes over the yoke to allow the hammer boss tool to double as a yoke face reamer tool. All sitting in the cart at Power custom

I ordered a lightened firing pin spring and replacement firing pin from Apex today. I think I could have had just as good of luck keeping the .495 S&W pin and clipping the spring but I wanted to check out a side by side of Apex's product. Plus, they were pretty informative on the phone today.

 

[tomcatt51]

Pdxrealtor, you need to free up some space for incoming pms.

 

[Pdxrealtor]

Done........