I plan to eventually build a .450 N.E. on my Zabala 10 Ga. To gain experience I am making a 30-40 Krag rifle barrel with a new monoblock for my Savage 220 single shot. The process seems pretty straightforward. One of the questions I have right now is: Why solder the barrels to the monoblock as shown in Mr. Browns book? Why not just thread them like a bolt gun?