Hey guys,
This is a newer 586-8. The cylinder is slightly rough to open. Would you consider the length of the center pin to be the primary cause? If I have my lingo correct I read this as 29 thousandths, is this the correct reading on the calipers? I'll also consider polishing the extractor rod bolt if that will help.

The center pin is too long, if, in the photo, you are depressing the center pin at the breech end to the point where it is even with the boss on the extractor face.

Ideally, when the thumbpiece is fully pushed forward, the muzzle end of the center pin should come even with end of the extractor rod, or just slightly beyond the end. (+.010")

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

Take the cylinder out, put it flat against a hard surface so the center pin is sticking out and start filing it down, and like armorer951 said, either file it flush or slightly beyond the extractor rod.

__________________
Hello darknes my old friend

Was my wording for the measurement I took correct? 29 thousandths? So taking off 19 thousandths should smooth the cylinder opening?

I held the breach end of the cylinder against a piece of wood for the picture and measurement.

Yes sir, that looks correct. Suggest removal of sufficient material to make it even, or slightly longer (past) than the end of the extractor rod. The .010" was a suggestion about the limit to it's being out past the end of the rod.

I would just take material off the end of the pin by stoning or filing until your opening and closing feels "normal". The end does not need to be polished. Check the end of the extractor rod and front locking bolt for evidence of burrs too, while you're at it. Check them with a magnifier.

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

Is it ok to smooth the opposite (breach end) of the center pin? It has an edge on it.

I'm not sure what you mean. The crowned (rounded) end of the pin could be polished with crocus cloth or similar. I wouldn't change it's dimensions or length. If it's a burr then it could be carefully removed.

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

I shortened the center pin and polished the bolt. It improved a bit. I know its not supposed to just flop out but thought it might improve more. Thanks for the help!

Could also be related to the way the front locking bolt was originally fit to the gun at the factory. Fitting of that particular part is very important in terms of how easily the cylinder opens and closes.

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

I checked for deflection of the extractor rod on all cylinder positions. There is very slight upward deflection on all cylinders. The shop manual says "stone the bottom of the bolt". I don't fully understand the procedure to stone on one side of the bolt since the whole thing is basically round and tapered. I didn't want to put a flat surface by "stoning".