@Bob Wright ,
Get enough lathe. Having a spindle that can swallow the whole action, not just the barrel, can be helpful. We're here to help when the time comes. A lathe with a clutch and a brake go a long way toward sanity when doing breech and barrel work. Prismatic ways are a must as is a gearbox. VFD drives have simplified some things. A quality wedge lock tool post and three times as many tool holders as you think you'll need. (a good milling project)
Find an "Elmer" that not only knows milling machines but the Bridgeport in particular. They have genetic as well as individual traits.