You don't want to change the surface characteristics of a barrel is his explanation and you don't want to take the sharp edge off the rifling. You didn't run JB in that Sako did you?
No, the sako didn't need it. It was baby smooth from the start. Your gunsmith near your home, who are proud of thier prices, recommends JB. I was in your and your gunsmith's camp before using a hawkeye bore scope. I never saw any rounding or edge changes with JB's. Its such a fine grit abrasive it would take 100's of strokes to round your edges. I watched this carefully before and after each use. I know what he is saying however. Not to irriatate the surface, instead seal it. But oldelk, if you got a gun that is so rough it takes 2 hours to clean the bore, irratating the pours of the metal really takes the back seat. I would never do it to a match barrel, and never have. A crappy rough bore surface characteristics won't matter. If its a turd, its a turd.
I know the hawkeye is expensive but I rented one thru my gunsmith with the understanding if I broke it, I bought it.