blackhawk scope mount hunting ?

[MH357]

I have a ruger blackhawk with a 4 5/8 barrel that I am thinking of hunting with. I decided on luepold mounts (dont trust b-squares or wish to mark up my barrel). so I need to drill and tap the top of the receiver. I was thinking of mounting the base with the existing hole from the removed site and use the base with a tight fitting drill to mark the center of the holes. To get the sight on straight with just one bolt in it (if the humps on the sides were the rear sight was do not line it up for me), I will use a set of calipers I guess. The drill should be a number 31 and tap size 6-48. Do I drill all the way though or stop at a proper depth?

Any advise would be great. Only local gunsmith in my area has a very bad reputation not trust worthy with his work. Plan on useing a nikon 2x20 scope and don't plan on shooting past 75 yards. Will short barrel and scope be ok?

Thanks MikeH