+1 On Karl but he limits what he can/will do these days but none better than Karl.
Another option if you want someone in Idaho and I think is out of Boise is Norbert Costa, think is outfit is called Sure Shot Precision Rifles. He built a rifle for a guy I know a bit and its a hammer. Supposed to be a nice guy to work with.
Looking to have a muzzle break installed and some coating done . I think Karl would be a great choice but I don't want to deal with shipping on this project.
Check out this website. http://muzzlebrakesandmore.com/Home_Page.php
Nathan does awesome work. He just installed his own muzzle break on my 300 RUM, it now has the recoil of a 243.
Give him a shout