My Smith 627 has a .010 cylinder to barrel gap.

Its very accurate (by my standards) and does not splatter (that I can feel) but does show a lot of smoke/fouling on the cylinder after 20 rounds or so.

I' ve heard that the barrel can be machined to reduce the gap.

Do you know any good gunsmiths capable of this kind of work (in Southern Ontario). Any suggestions?

It' s a real beauty - I' d rather do nothing than risk screwing it up.

It' s gap between the cylinder and forcing cone. Yeah the closer the better but i would leave it alone.
When you say splatter are you talking about the burn ring that develops on the top strap?
if you want to remove the burn rings from your cylinder get you some lead away clothes. takes the burn marks right off. looks new!

Now hog we have got to figure out how to get that 627 across the border so we can make a deal!

Although the gap seems a bit much, I would not mess with it if it shoots well. We used to set the gap at .006 with our Dan Wessons for combat shooting with lead bullets. You need a little more gap for lead bullet. Any good Pistolsmith should be able to take care of the problem. Get a few refferences as a good Gunsmith will give you a few customer names that you can check with.

This gap is normally between .003" and .004" , or JUST ENOUGH TO PERMIT THE CYLINDER TO ROTATE FREELY AFTER IT BECOMES FOULED DUE TO FIRING! But, to change yours, the barrel will have to be SET BACK IN THE FRAME perhaps one thread, and then have the barrel face and forcing cone refitted.

Hog, may be a dumb queston, are you pushing the cylinder foward when you check the gap?

Huh,

This may be a stupider answer.

I didn' t know I was supposed to push the cylinder forward...it doesn' t move much.

Hog ole buddy, the foward and aft movenent of the cylinder is called endshake. When you pull the trigger, the hand that indexes the cylinder will also push the cylinder foward. If you have excessive endshake ( more that .002" ), it needs to be eliminated before the gap is re-adjusted. You might have .005" endshake, your cylinder gap would be .005" . If you reset the barrel, when the cylinder is pushed foward by the hand, you' d have no gap, cylinder would rub on barrel.

To set clearance, they remove stock from the barrel face that butts up to the frame the equivalant of one thread. Then they face the barrel to give you the .005" gap, and re-cut the forcing cone.