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.