Dear friends, I recently acquired a 66-2, although the precision is excellent, you notice a small movement of the cylinder, back and forth, being closed, it gives me a measurement of 0.003 when pushing it forward (against the forcing cone) and 0.006 making the rear stop, is that play excessive? Another thing that caught my attention was that when measuring from left to right, that is, from the cylinder opening side, it is slightly easier than when doing it from the other side ( right to left), is that normal ?, a hug for all.
CYLINDER SHAKE
- Thread starter GOLDOT
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Not unusual that the front gauge would be a little more on one side than the other. The barrel extensions in those days were filed by hand, instead of using a piloted facing cutter. If (when) the fitter wasn't good with a file....well, you know.
Three thousandths of an inch is not excessive end shake. Some gauge in the cylinder assembly is needed for proper function. Ideally, you want the gap at the barrel cylinder interface to be .004" - .006". Yours at .003" is a bit tight, but function should be fine if the gun is cleaned regularly, particularly the front face of the cylinder.
Three thousandths of an inch is not excessive end shake. Some gauge in the cylinder assembly is needed for proper function. Ideally, you want the gap at the barrel cylinder interface to be .004" - .006". Yours at .003" is a bit tight, but function should be fine if the gun is cleaned regularly, particularly the front face of the cylinder.
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Your 66 should work fine as it is, that said if you'd like the experience of doing it and the peace of mind knowing it's right you can easily purchase endshake shims in .002" thickness and set one in there which would then put you solidly inside the factory specs.
Shims can be had from Triggershims.com , Midwayusa, Epay, etc. for $6-20 a packet.
Shims can be had from Triggershims.com , Midwayusa, Epay, etc. for $6-20 a packet.
Thank you very much for your answers, I don't know if it would be worth making the adjustment, the problem is buying from my country, Argentina, generally they do not send anything that belongs to the weapons category, I will try anyway.
Ah, if it's a pain I wouldn't bother too much about it.
In the pre-shim days a gunsmith would use a dulled tubing cutter to stretch the yolk, there are videos on youtube of how to do it and it is true that the more you shoot a loose gun the looser it gets. If you plan on putting thousands of rounds through it as part of regular training you might want to do it but if you are a 100 rounds a year user it's fine for the rest of you natural life.
In the pre-shim days a gunsmith would use a dulled tubing cutter to stretch the yolk, there are videos on youtube of how to do it and it is true that the more you shoot a loose gun the looser it gets. If you plan on putting thousands of rounds through it as part of regular training you might want to do it but if you are a 100 rounds a year user it's fine for the rest of you natural life.
So you're saying that you have .003" end play.
That's a bit too much end play because as you posted, you can feel the movement. But if you eliminate it or even reduce it by only .002" with a .002" shim placed in the yoke axis shaft bore of the cyl (this shims the back of the yoke axis shaft), your bar/cyl gap space will widen from the .003" minimum to .005" (resulting in a cyl end play of .001"). That would be ideal end play but on the tight side for the bar/cyl gap as posted above. If you don't have forcing cone contact with the cyl face once the cyl heats up from firing and/or caused by fouling on the cyl face and forcing cone now, you won't after the change. If you do have it now, you'll know because cocking the hammer or firing double action will not be able to rotate the cyl.
Shims are cheap and easy to install, give it a try. If you are experiencing the above problem, take .001" off of the forcing cone.
If you want the "gold plated' way to reduce end play, replace the gas ring at the front of the cyl axis bore; that's usually the point of wear that causes the end play if the gun didn't come new with the play. Fit the new gas ring to the yoke .002" -.003" longer than the original.
Whichever way you choose, the bar/cyl gap may still need adjusting; you'll know after you shoot it if you can't cock the hammer or pull the trigger.
That's a bit too much end play because as you posted, you can feel the movement. But if you eliminate it or even reduce it by only .002" with a .002" shim placed in the yoke axis shaft bore of the cyl (this shims the back of the yoke axis shaft), your bar/cyl gap space will widen from the .003" minimum to .005" (resulting in a cyl end play of .001"). That would be ideal end play but on the tight side for the bar/cyl gap as posted above. If you don't have forcing cone contact with the cyl face once the cyl heats up from firing and/or caused by fouling on the cyl face and forcing cone now, you won't after the change. If you do have it now, you'll know because cocking the hammer or firing double action will not be able to rotate the cyl.
Shims are cheap and easy to install, give it a try. If you are experiencing the above problem, take .001" off of the forcing cone.
If you want the "gold plated' way to reduce end play, replace the gas ring at the front of the cyl axis bore; that's usually the point of wear that causes the end play if the gun didn't come new with the play. Fit the new gas ring to the yoke .002" -.003" longer than the original.
Whichever way you choose, the bar/cyl gap may still need adjusting; you'll know after you shoot it if you can't cock the hammer or pull the trigger.
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Actually, the use that I give it is approximately 100 shots per month, with 38 SPL or 357 Magnum reduced to that level, my question is whether it is justified to adjust it so much, to the limit of producing the friction with the forcing cone.
Adding end shake yoke shims will reduce end shake you now have, which is currently acceptable, but, adding the shim(s) will move the cylinder back (away from the barrel extension) by the thickness of the shim that is added , and increase your current barrel/cylinder gap.
Opinion: Since your current situation is in spec., further intervention is not needed at this time.
Opinion: Since your current situation is in spec., further intervention is not needed at this time.
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While many here produce facts and opinions that border on the miraculous, we all know a couple of things for sure......none of us can be in two places at once, and none of us can accurately predict the future.
Enjoy your model 66. Another thing we do know for certain.......with proper care and maintenance, your revolver will outlive all of us.
Enjoy your model 66. Another thing we do know for certain.......with proper care and maintenance, your revolver will outlive all of us.
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You'll probably never have to even think about it again in your lifetime with that shooting "diet".
Does the yoke have any end shake?
"Enjoying" the quarantine and the rainy weather, I decided to disassemble the 66, which I instantly noticed the edge of the gas ring, it has wear and an irregular shape, that is, small missing materials, surely the punishment of the recoil , from what I've been reading on this forum, the correct thing to do would be to replace it. Reading Dick Baker's article on "Revolverguy.com", due to the ring slipping out of place, his text: "I added a notch in the cylinder bore for the ring, and pressed a new designer gas ring ( with internal belt) in its place so that it would be blocked". I don't know if you agree with me that the ideal is its replacement, the issue is that only in found rings without this design, someone knows where I can buy it. A hug to all.
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The gas ring's one and only job is to mitigate dirt, and atomized shooting debris and gasses from entering the yoke cavity and interfering with cylinder rotation. The gas ring has no function whatsoever with respect to maintaining, or contributing to the cylinder assembly's proper "in battery" position on the yoke barrel. (cylinder closed)
If there is contact between the gas ring in the cylinder and the collar on the front of the yoke when the cylinder is closed, then the gas ring was not properly installed and/or fit when it was at the factory. (unless the ring has been modified since that time)
If necessary for proper rotation of the cylinder, in your case, you can move the cylinder assembly away (back) from the yoke collar by installing a .002" yoke end shake shim.
Another viable alternative would be to shorten the gas ring extension so that it clears the collar at the front of the yoke when the cylinder is closed.
Another consideration to keep in mind is that the incidental contact between the front edge of the gas ring and the yoke may be occurring when the cylinder is open, not when the cylinder is closed.
If there is contact between the gas ring in the cylinder and the collar on the front of the yoke when the cylinder is closed, then the gas ring was not properly installed and/or fit when it was at the factory. (unless the ring has been modified since that time)
If necessary for proper rotation of the cylinder, in your case, you can move the cylinder assembly away (back) from the yoke collar by installing a .002" yoke end shake shim.
Another viable alternative would be to shorten the gas ring extension so that it clears the collar at the front of the yoke when the cylinder is closed.
Another consideration to keep in mind is that the incidental contact between the front edge of the gas ring and the yoke may be occurring when the cylinder is open, not when the cylinder is closed.
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That's correct. Bearing contact between the cylinder and the yoke occurs at the interface of the breach end (rear) of the yoke barrel and the bottom of the cylinder's yoke cavity.
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