I use the dovetail method simply to get the lug as close to the barrel as possible, and still have a good solid barrel to lug mating base. If I were using a round barrel then I would revisit my choice as it would be easier, for me, to install the lug with solder than to file the dovetail in the barrel. I don't have a milling machine so all my metal work has to be done with hacksaw and files, which is just fine, I've installed a goodly number of under lugs and sights using nothing by these hand tools, it just takes time. The one time I had a dovetail cut into the barrel by machine it was done by a good fiend of mine using his lathe, yup it can be done that way, he chucked the dovetail mill up in the chuck and then put the barrel in a vice attachment and moved the barrel across the cutting tool, the problem came about when the chuck let the cutting tool move outward and the dovetail configuration of the tool caused it to dig deeper than we wanted into the barrel, almost too deep, much more and it would have come through into the bore necessitating cutting the barrel off back behind that dovetail, using the shortened barrel in another project and purchasing a brand new barrel and starting over. After that little experience I went back to my hacksaw and files, much more controllable.