Thanks to all above who have replied. Jim you are right about my error, I meant to say 16 yards not feet (I'm still looking for the "yard" key on my keyboard).
Yesterday, I shot the gun at the patterning board at my local SC range. Both barrels shot spot-on; printing exactly on top of each other. Yes, my mount is consistent. The hits are all exactly in the same place (2" left) indicating the need for a slight cast-off of the stock. No surprise since I'm right-handed and the stock is cast neutral. Now I have learned that the it's the point of my EYE on the stock that needs to move 1/8"; the butt of the gun will move slightly more.
Thanks again.
