I have a ruger blackhawk and I want to have a heavy 10" stainless barrel put on, replacing the short barrel. Do you know of gunsmith specializing in this type of work?....belt-loop@cox.net
Check out Hamilton Bowen (http://www.bowenclassicarms.com/). He's expensive, but the best there is... and you might drool so much over some of the adaptations to the basic Blackhawk depicted on his Web site that you may want him to do something similar to yours, long barrel and all!
His "Taylor Throating" procedure might be a nice addition to a barrel swap job (cheap accuracy boost at a cost of 50fps or so from what the barrel length would otherwise do, see also his website).