Obviously, the rifle shoots to the right with centred sights. Reasons for this have been given, except as well, the 'cutting' of the crown can also
cause this. If the "cut" crown is even all the way around, same height and depth, then this is not the problem. The hole in the bore, the last few
inches determines the direction of travel of the ball or bullet. If the barrel is straight, no bends, then hole inside must not be exactly in the middle
of the bore the full length of the barrel. Everything works in concert with each other and all must be right for the ball to travel true when the sights
are perfectly centered. This is quite normal with a lot of today's barrels. If "out" is it usually only an inch or so.
I have seen only one barrel that was really bad and that was a .50 cal GM barrel that was bent. This was replaced with a new barrel, and with sights
perfectly centered, so was it's shooting. Bent barrels do happen. It doesn't take much of a bend to land the ball off centre 3 to 4" at 30yards.
Good shooting, btw.