I recently picked up a model 60 with an improperly fitted(probably not fitted) yoke screw installed. Thanks to those that helped in guiding me in the ways of fitting it. Upon further inspection I noticed the the outer part of the cylinder on a charge hole made the slightest contact with the forcing cone. Of course me being a novice(I consider myself more skillful than bubba), I jumped to the conclusion I had end shake or end play. I've spent some time detail stripping the cylinder and ejector assembly and found nothing out of the ordinary. I reassembled it and checked again. Sense my feeler gauges are cheap the thinnest I have is .008 and it slides in tight on every charge hole. Two are snugger than the rest. The two snug ones are the two charge holes in question. The .008 FG doesn't fit in any gap with pressure applied to the cylinder. I inspect each charge hole and find that two of them just barely come into contact with the FC and I mean barely. To the point I think I see light, but I know that's just me. It is touching, IMHO. Just on the top if looking at it from the side, just under the top strap. The bottom of the charge hole is close, but light still passes through. This is only when I pull forward on the cylinder. I plan to shopping for better feeler gauges, but I doubt this is a seriou end play issue. Am I correct? I scratch my head because it's only two charge holes.

Edit to add: Model 60 no dash. Circa 1979-80.

Is the forcing cone cut 90 degrees or is it off a bit ?

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1st smiles,lies.Last,gunfire.

I'm ill equipped to to precisely answer that question. However, I can tell you that OAL length at the top of the FC to the muzzle is .003 longer than the bottom of the FC to the muzzle. That lends me to say no. It's not absolute 90 degrees.

Well. My new feeler gauges are much more informative. End shake appears to be .006. Measurements range from .008 to .002 on the larger of the cylinder gaps, to .007(sticks 1/8 way in)/.006(fits better) to .00125 squeezing in at the bottom of the FC. Those still touch the top of the FC.

What's the rear gauge or "headspace" measurement?

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Ret. LE, FA Instr, S&W Armorer

Head space is at .008. I did install 2 of the .002 Power Customer bearings. End shake/play is very slight now. If my math is correct, I come up with .00125 to .002.

Rubbing takes place when the cyl warms up from shooting usually, if you have the following issues:

Whenever you see the light space at the cyl gap, it should be an even space top to bottom. Since you have rub marks at the top of the chamber throats the FC is likely not square.

But why only rubbing on two chambers? Because the front face of the cyl is not perfectly square to the FC; the cyl face has "run out", or ever so slightly tilted on the yoke shaft. This is not uncommon.

You did the right thing first. Do you still have cyl rubbing?

If so, slightly stone the FC, only at the point where it rubs the cyl face.

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Jim
S&WCA #819

Thanks for the informative reply. The rubbing on the forcing cone is no longer taking place. I'm optimistic that my range test this weekend will be informative in a good way. I've checked everything I can and believe she's a go for the range. I've also found that the FC is not as far out of 90 degrees as I thought. I agree with your diagnosis of the possibility of slight cylinder run out or the ever so slightly tilted yoke shaft. Neither of the chambers in question are coming close to touching the FC at this time.

I expect you got that measurement over cartridge cases, which is close to worthless. The range of acceptable headspace is 0.060-0.068 inches rear of cylinder to breech face.

If you've got recessed chambers, break down and buy a GO headspace gauge. Measure rim thickness and use feeler gauges. The total should run within the range above.