I have an early model 18 revolver that had about .004 endshake. The gun has also been having a lot of misfires so I corrected the endshake with endshake bearings from Triggershimsdotcom. The endshake is now reduced to about .001 or less and the cylinder rotates freely when the gun is cold and hot and it opens and closes normally. The gun has since been fired about 300 rounds without a misfire. However, there is one problem. With the cylinder open to load the rounds, there is a very slight drag on the frame lug when the cylinder is turned when loading. It’s barely noticeable. The bluing has now worn off the cylinder where it contacts the frame lug. I’ve considered replacing the endshake bearing with a thinner one which will reintroduce some of the endshake, but that would be like allowing the tail to wag the dog. I think that the most logical next step would be to file the frame lug to allow more clearance. However, I don’t want to do anything more that will deface the gun. There is already the loss of bluing on the cylinder. Has anyone ever experienced this? Thanks in advance.
S.K.

I would recommend that the frame lug not be altered as once done there is no turning back. Instead, change the shim to a slightly thinner one. End shake in the order of .002 is nothing to be concerned about. You might try removing the shim that you have installed and sand it with a very fine grit and keep trying it until the contact with the lug disappears. This will allow you to get the minimum of end shake.

I recently tightened up my 18-3 using endshake bushings and yoke shims from Brownell's. The yoke shims move the entire yoke forward slightly both decreasing BC gap and increasing cylinder to frame lug clearance.

Disclaimer: I am certainly not a gunsmith, but these shims were easy to install and worked just fine on my revolver. YMMV

Some incidental contact between the frame lug and the rear of the cylinder, and the resulting effect on the finish is inevitable and normal. Constant rubbing/contact at this interface when the cylinder is open and being rotated during loading is not normal.

If your rear gauge, or "headspace" (measurement between the rear of the cyl face and the breechface) is correct, or .008" - .010", you could substitute a thinner yoke shim that would increase your endshake slightly, perhaps to a total of .002", without sacrificing reliability in the process. This would restore the correct gauge between the lug and the rear cyl face.

__________________
Ret. LE, FA Instr, S&W Armorer

I have never tried using yoke shims. How well do they work?

They work very well. One thing to remember is to properly prep the "bearing surfaces" on the end of the yoke barrel and one the inside of the cylinder before the installation of the shim or shims. In order for the shims to work properly, these surfaces need to be checked and "trued up" if needed. The shims also allow changes to be made in the adjustment of the fit, without removing material from the end of the yoke barrel if it's overstretched, thus preserving what material is there, rather than repeatedly stetching and fitting.
Also, additional shims are easy to add in the event further lengthening is required.

I have used "triggershims.com" in the past. Free, prompt shipping and high quality products. Mr. Shively is quick to respond to e-mails and questions too.

__________________
Ret. LE, FA Instr, S&W Armorer

I want to thank everyone who replied to this thread. Today I removed the endshake shim and replaced it with a shim that’s .001 thinner. Prior to doing this, the minimum endshake was about zero and the maximum endshake was .001/.002 on the opposite side of the cylinder. Now the maximum endshake is .002/.003. I went to the range and fired 200 rounds and there were no misfires. I also noticed that after about 100 rounds the endshake seemed to increase. I didn’t have a feeler gage with me but I’m sure that it increased based on feel. Could this be due to the frame stretching slightly after firing?
Also, the cylinder when opened for loading now has about .001 play (clearance) from the frame stud. I don’t know if this is sufficient but the cylinder doesn’t feel like it’s dragging on the stud when loading.
My next question is what to do about the worn away bluing on the cylinder where it was rubbing on the frame stud. I have no experience with cold bluing products and don’t want to make it worse. Does anyone have any experience with this? Once again, thank you for all the input.
S.K.

Don't be too concerned about end shake as long as the rear gauge, or headspace measurement remains in spec. (.008" - .010") There does need to be adequate room in the assembly for lubricants, and for expansion of the components during firing.

Remember too that all revolvers benefit from regular, complete cleaning.... especially .22 rimfires. "Residue" from firing, including atomized combustible components, unburned powder, and bullet lubricants can often cause or contribute to reliability issues.

Reference your bluing question.......In the past, I have used Brownell's "Oxpho-Blue" for touch up of small areas. Be sure to follow label directions carefully.... degrease first, then apply to the area using a clean patch or q-tip. Use sparingly, protect your hands and eyes from contact. Be sure to re-hydrate the repair with a high quality oil when the job is completed. Although not necessary, the bluing can help restore the finish, and reduce the cosmetic "damage" caused by the contact of the lug.

__________________
Ret. LE, FA Instr, S&W Armorer

I would like to point out that ANY endshake is not acceptable. Anyone well versed in the operation and mechanics of revolvers should know this.

The presence of ANY endshake will just get progressively worse as you continue to fire it. When endshake is present, the cartridge fires thrusting the cylinder rearward which hits the ratchet off the breech face and then rebounds back forward, which in bad cases it will then hit off the forcing cone. If it is not doing this already, it will. The less endshake, the less it batters itself, but it does so nonetheless and WILL get worse. The more endshake that exists, the more room there is for the gun to batter itself, and it will get worse faster.

Point being, endshake in any amount in unacceptable in a firearm that will be used regularly, as it will eventually batter itself to destruction. Sorry to be so negative, but it's a fact. A properly fitted revolver from the factory should have no endshake at all.

Hadn't heard of those guys before. Just got on their site and ordered both cylinder and yoke shims. Nice they take PayPal and shipping is included.

In response to post #9:

I have to disagree, although I should apologize, as I am perhaps not as "well versed" as some, as I only have 36 years of revolver armorer's experience.

I'm totally mystified as to where this notion of "zero" endshake, or "no endshake at all" as you call it, ever originated. Endshake, or gauge in the assembly is not only acceptable, it is required.

First, concerning your description of what happens to the cylinder during detonation, the ratchets never touch or "hit off the breechface" as you indicated....contact between the extractor and the breechface is confined to the extractor boss that surrounds the center pin hole in the extractor body. Wear and tear (not impact peening alone) on the components, including the bearing surface at the rear of the yoke barrel, the bearing surface inside the cylinder at the rear of the yoke cavity, the boss on the extractor and on the breechface itself, ocurrs both during detonation, (by direct and rebound impact) and when the cylinder assy rotates on the yoke. This wear is exacerbated by dirt and debris. Zero endshake will not serve to mitigate this inevitable wear, because the gun cannot function with no gauge within (or between) the assembled components.

Zero endshake is impossible in the assembly, because, by definition, it leaves no room for the components to function. The cylinder and other moving parts simply will not freely rotate as they are designed to do, and in this "zero" endshake scenario you describe, the cylinder assembly cannot even be opened and closed. Add in the inevitable dirt, shooting debris, generated heat and your favorite lubricants and, even in a gun that is cleaned regularly, you have a revolver that simply will not work.
Your comment that in the presence of any endshake the revolver will "batter itself to destruction" improperly assigns fault for "destructive" wear to a single origin. The "destruction" or degredation you allude to is common to every mechanical device, and in the case concerning revolvers it's cause should be attributed to a number of factors, not just the presence of endshake. Righty attributed, the causes must also include: normal contact/friction degredation, neglect, abuse, oxidation and improper use. (and some others)

If the original "factory" fitting of the revolver was done completely and properly, it will have adequate gauge in the fit components, including the required "endshake" if you want to call it that. During the subsequent life span of the gun, the only fitting concern regarding these component parts with respect to the proper position of the cylinder in the frame is the front and rear gauges. If the front and rear gauges are correct, and meet specifications, then, barring any other repair concerns, like the integrity and proper position of the yoke for instance, the revolver in question will operate and function as intended. Stretching of the yoke barrel or the addition of shims may become necessary because of an out of spec condition (wear resulting in an open rear gauge condition), but the focus of the repair should be to restore the rear gauge so that it is within the proper specifications, not to push the cylinder back into a zero, or "no endshake at all" endshake condition.

__________________
Ret. LE, FA Instr, S&W Armorer

Thanks again for your reply. I have since ordered the Oxpho-Blue from Brownell's.
Also, what is headspace that you mentioned and how is it measured? I think I know but not sure. Thanks again.
S.K.

Headspace is measured with feeler gauges. Measurement of the rear gauge (headspace) is made by placing the appropriate thickness gauge between the rear cylinder face (cyl closed and empty) and the breeechface. These surfaces should be cleaned, and any residue wiped off prior to measuring.

The feeler gauge should be inserted between the rear of the cylinder and the breechface in the area just below the top strap. In the case of your model 18, the measurement should be between .008" and .010".

__________________
Ret. LE, FA Instr, S&W Armorer

Thank you. Is that measured with the cylinder pushed back? If so then the gun is in spec.
S.K.

There is some additional information under the "FAQ's" section at the top of the "S&W - Smithing" forum division.

Note: Scroll down the page until you see "Feeler gauge inspection". When the poster refers to "air gap" he is referring to the front gauge, or barrel/cylinder gap.

__________________
Ret. LE, FA Instr, S&W Armorer

As a result of my lack of experience with using yoke shims, I'd like to ask a question about their use. It seems that using a yoke shim has the effect of reducing the cylinder-barrel gap. So it also has the companion effect of increasing the headspace between the rear face of the cylinder and the frame. So what is to be done about that? Ignore it?

You shouldn't need a yoke shim unless there is endshake on the yoke itself, due to improper fit between the yoke screw and the button on the end of the stem.
You are correct in your assessment about adding the shim to the stem. Adding a shim to the stem of the yoke will move the assembly forward in the frame window.....and thereby decrease the B/C gap and increase the headspace. If this results in the cylinder being out of spec, you can always add a shim to the end of the yoke barrel, which will move the cylinder back the desired distance.

__________________
Ret. LE, FA Instr, S&W Armorer

Very good information there. Thanks again.
S.K.

WOW, some very well written and educational information there. Thanks for posting that.

__________________
James Redfield
LM #497