The statement that amazes me on Dan Newberry site, is that the "scatter node" and the OCW have any kind of fixed relation to one another.
He states clearly that the group center is the focus of the OCW. He ties the change in group center to nodal barrel harmonics. All this makes perfect sense and is easily demonstrable.
Then he says that the "scatter node" is due to bore oscillation, and ties it to the OBT theory of Chris Long. Again, that all makes perfect sense. The bore constricts and dilates. This will obviously have an affect on the group size.
The part that makes absolutely NO sense, is that these two effects are in some fixed relationship. They are completely independent effects that have nothing to due with one another. Thier relationship to one another is affected by barrel length, barrel stiffness, seating depth of the bullet.
In any given rifle, the barrel length and stiffness are a fixed quantity. The factor that CAN be changed is seating depth. Changing seating depth does not change the position of the group center consequentially. It has a dramatic effect however, on group size and shape!
Tune the group center with powder charge.
Tune group size/shape with seating depth.
Stop relating the two.