Thanks Scooter just the info I needed! I have just bought a N.O.S. never shoot Model 17-4 in 8 3/8 barrel. Want to mount my Leupold S&W kit I found on it but since it's a dash 4 it needs to be drilled. Don't think there's a gunsmith anywhere near where I live so apprehensive whom to chose? If I can't find someone capable is there a company that specializes in this type work? thanks