Hey guys,
I just started shooting my 686 N-D 4" and love it shooting plate matches but there is a problem that I have with the cylinder sticking on two holes after it get a little dirty. Check out the pics and see what you think. Only two holes and only when it gets fired a bit. On the barrel face you can see about 7:30 to 9:00 where it scrapes, and on the cylinder face fore and aft of the one hole. I can't shoot matches completely since it locks up and I have to go to the truck and brass brush the face to get it to rotate again. Any thoughts? there is .009" cylinder gap on the good holes and on the two sticky ones there's .009" on the right side and .005" on the left where it sticks. Any help is appreciated.

Attached Images

	686 forcing cone.JPG (37.0 KB, 51 views)
	686 cylinder face.JPG (61.4 KB, 64 views)

It would appear you have non-square cylinder face. The high spot where shown pretty much indicates it. It can be corrected, but by a trained gunsmith with the correct. tools. It may be best done by the factory. First thing though, have you cleaned it well under the extractor star? A similar condition can present by residue there. Non-burned powder granules (especially larger ones like Unique) can lodge nearly unseen but keep that one point raised up enough to cause binding. (I learned this be having that condition on a Pre 27 years ago). Be sure when cleaning use a brush, and plenty of solvent. When extracting spent rounds be sure to eject with the barrel pointing straight up, not sideways.

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H Richard
SWCA1967 SWHF244

How much end shake do you have? You may be able to add a shim to keep it back away from the forcing cone.

I'm going to call S&W tomorrow and see what they say. I'm with you on the non-square cylinder face, that's where I was leaning. I did clean under the star and that helped a bit and even if I shim there's still the fact the cylinder is not square so my space will increase all around. Keep you posted an what I get from S&W and where this may lead.

Just feeler gauge your gap on each chamber. Use a small wooden wedge or light force pushing the cylinder forward when you measure. Very simple, and will confirm if your cylinder face is off. Normally two chambers will be tight but sometimes three. This condition is not that uncommon

I spoke with a nice gentleman, I belie3ve his name is Dan, from S&W and he thinks it's endshake like BIGGGBBRUCE mentioned. He spent a lot of time with me and asked many questions to come to his conclusion and said if I if it "clicks" moving it front to rear then there's too much clearance Clarence, and it does click so I do have a fair amount of movement. I ordered a shim kit from triggershims.com and they should be here tomorrow, .002" & .004". Dan stated that when they are tuning the revolver, after setting the cylinder gap a rod (range rod) goes into the barrel and down the pipe to align with the cylinders. If it does not align then they twist the frame until tolerance is met, and that is why I can get a .009" reading on the right side cylinder gap and a .005" gap on the left, it's very common. All of my cylinders I found are tighter on the left side than the right......who knew? I'll keep you all posted as I continue and thanks so much for your input and keep the thoughts coming, I love learning about the S&W revolver.
BTW- Is there a torque spec for the side plate screws? I have a nice Snap-On torque screwdriver (QDriver4) which was recently calibrated at Snap-On and would like to stay constant with my tightening proceedure.

And the factory thinks that end shake is causing just two chambers or roughly 120 degrees of your cylinder face rubbing ? How do they explain end shake clearance causing only a portion of the cylinder face being out whack.

Good luck

I guess...... like I stated, he said that tweaking the frame for the barrel/chamber line-up will cause the oddity in the gap. My thought on that is, then where do you measure the gap from, right or left side? Oh well, I'll see......he said I can always send it back to them to see what's up.