Sticky revolver cylinder

I have an S&W 586 that I bought new in 1985. It has only been used for bullseye shooting and in it's 37 years has only fired 25 rounds of magnum. Other than that, it has only fired 148gr HBWC in the 1000's.
I have noticed that one of the charge holes sticks in double action. I pull the trigger, the hammer half cocks and locks up. It does it consistently 
with the same charge hole. It would do it even if the gun was empty.  Single action I have no issue, just double action. I noticed a very tiny burr on the ratchet (star) and carefully stoned it off. I cleaned under the ratchet, cleaned the trigger and hammer internally and reoiled. Right now the problem seems to be fixed. The lock up for all charge holes is solid and timing is perfect. What do you think may be the issue. When I shoot bullseye, I shoot double action for timed and rapid fire b/c the hands don't work like they used to when I could cock the hammer each time. So this issue is concerning. 
mustachio
Here is the 586: 

Make sure gun is empty.

Point gun vertically downward. Try firing double action.
Point gun vertically upward. Try firing double action.
Was the symptom the same?

Remove the cylinder, or swing it out. Hold back on the cylinder latch and pull double action as mentioned above.
Was the symptom present?

Have you taken off the side plate to see what may be going on? My hunch is that it has something going on with, or interferring with the hand.

Did all that you suggest...no binding at all.
I did take off the side plate and clean out the little gunk that was there.
I judiciously oiled it and it seems fine now. I shoot my match tomorrow
(Wednesday) and that will be the real test. Hopefully, I just had a burr
and some dirt. Otherwise, never a problem in 37 years.
thanks for your suggestions.

Shot the 586 today and had the same issue after 30 rounds, after the gun heated up. I took it to a local GS who has a great reputation in S. FL. He said he really could not find anything wrong with the ratchet, hand or ejector rod. He did note that the forcing cone was not cut exactly square and was longer/angled on the bottom than on the top.  He suggested that I clean the face of the cylinder and forcing cone face of a very small amount of lead build up. If that does not work he will square the forcing cone to the face of the cylinder. He said the cylinder gap was smaller on the Charging hole in question b/c of the angle on the forcing cone. He said for me to do the initial cleaning before any work on the forcing cone was done to see if it clears up the problem. I can do that and he did not charge me for the 1/2 hour we spent together diagnosing the problem. I will do as he asks and see if the issue is resolved.

Lead under the gas ring?  Bent yoke?

My guess is fouling and needs to be cleaned on the gap, both cylinder side and the cone. If cylinder/hammer cocks half way this means that it initiates contact right where the fouling would occur at the cylinder end. No issues in SA because you are putting much more pressure on the hammer with your thumb. In DA you just feel it more. As far as the hand engagement goes the motions are exactly the same in DA as they are in SA, so this is not the hand side and from my experience not the cylinder stop. Must be on the forcing cone side. Now as to what causes the binding there it can be anything from fouling to bending. Especially noticeable when hot as metal expands and gap closes.

yoke and extractor rod are not bent

mustachio wrote:yoke and extractor rod are not bent

I had these exact symptoms in a Model 14, and I concluded the same as you.  I was absolutely certain the yoke was not bent.  Finally I gave up trying to fix it myself and sent the gun to S&W.  They diagnosed a bent yoke, replaced it, and the gun has been running perfectly ever since.

Wouldn't yoke be easily diagnosed by 1) put spent cartridges in and number them 2) see which cartridge sticks 3) unlock and spin cylinder into new position 4) see if same cartridge sticks or different.

gunsmith said yoke was fine. He said I had a build up of lead on the facing edge of the forcing cone and face of cylinder. I did a bang up job cleaning it and it spins freely and no binding. I will shoot Monday and see if my cleaning did the trick.

No cases stick in any position when I spin the cylinder...actually they never did...only stuttered after the gun got warm.

I think the issue is resolved. When the GS suggested that the forcing cone was not square to the cylinder I did a test. I did not have feeler gauge handy, but I did have some copy paper (like half the world) which mics at 0.004".  I cut a thin sliver and tried to slide it between the cylinder and cone. It would not pass through without bending. I did notice that the face of the cylinder had scratches on it where it was passing by the cone.

I asked the GS how he would fix the problem and he said, "like S&W would, the old fashion way using files and stones". I asked him if I used several different grits of Arkansas stones would I be able to do it? Response was, yes, go slow and measure often...classic "cut once measure twice" philosophy.

The angle on the forcing cone was visible to the naked eye, so I concentrated on the bottom of the cone, taking off a little and trying the paper again and again.

After an hour of judicious stoning the cone was starting to look "square" and the light between the cylinder and cone was becoming more uniform. I tried the paper again and it slide through without any binding on the bottom of the cone (which it had done previously). I then dress it up with a very fine grit stone so it was smooth and shiny.  I will estimate, which is the best I can do at this time that the gap is 0.004" plus a tad (b/c the paper slid very easily). I measured it with the cylinder forward in a cocked position. I have read that Factory specs for S&W are .004-.009-inches, so I believe I am in that factory ball park.

I am certain at this time that the gap was too small and leading on the cylinder face and forcing cone led to the binding. I shoot exclusively 148gr HBWC and that lead is quite soft...I hope this ends the "Saga of the Binding Cylinder."  Hey, that is a good title for a "spaghetti" western.

I will test this week and report back, hopefully with positive results.

Did you check to see if the cylinder had end play that possibly needed shimming to the rear to increase the cylinder gap before you started removing metal?

DA/SA wrote:Did you check to see if the cylinder had end play that possibly needed shimming to the rear to increase the cylinder gap before you started removing metal?

gunsmith checked all the specs and said no perceivable end shake.
with the exception of the flared forcing cone and some lead build up he gave it a good bill of health.
my gap is measured with the gun cocked for single action, so cylinder was fully forward.

However, I just ordered 2, 0.002 shims for the cylinder should it be needed.

shot a revolver match today and fired timed and rapid in DA. Not a single mishap. No cylinder binding at all. My table top gun smithing seems to have done the trick. When I got home I cleaned it of any lead to eliminate the possible issue in the future.

You probably already know this, but keep the area under the extractor star clean and dry. One unburned flake of powder under there might not be able to be seen, but can cause problems. Back when the dinosaurs roamed the earth, I would carry a cut off M-16 brush on a key ring, just for this purpose.