Good afternoon Gentlemen! So I have been working on my own 1911 made from an investment casting, got a great set of 3D solid models and blueprints from RifleConnection.com so I could add my own picatinny rail under the barrel and make a few modifications, my next step is to cut the barrel seat with a radiused ball end mill, what is the best way to control the depth of this if you do not have any read outs on the mill? By the way, that website has been helpful with a few builds!