Lol! Ok, in a perfect world, I can see how his hob method MAY have some positive effect. In the world WE live in, everything has tolerances, including the claimed angle of said leade and the hobb itself. If the two match absolutely perfectly, I can see the potential for improvement of the finish on the leade.
BUT...how cam pushing a tapered mandrel into a leade that doesn't absolutely match it not create a mashed area in the leade rather than evenly smoothing it out? Somethin's gotta give and metal be displaced in some areas more than in others.
Granted, he's doing it in barrels that only see soft lead bullets but I fail to see how this can be worthwhile or even something that should be considered doing to a new chamber and barrel. Things get pretty hairy quickly when dealing with small angles and even very tiny differences between the two angles of the leade and the hob. All I can visualize is lands getting "mushed out in some areas, or a portion of the leade having some purty serious burrs on the edges of the lands.
I'm very open to learning more about this process and hope you or someone can convince me how the "hob" process does more benefit than harm.
Remember, the man does his work on a dirt floor shop. I believe matching the two angles "EXACTLY" WOULD BE OF PARAMOUNT IMPORTANCE