I think there is an explanation on the first page of the document and IIRC it is interpolated data.

By the way I have some limited data for the 6X45 with the new AR Comp powder that I worked up if someone is interested.

Edited by venatic (11/02/11 11:30 AM)
"Anyone taking up handloading necessarily plays with unknown factors and takes chances. But so does anyone who drives a car,goes to a cocktail party,eats in a restaurant,or gets married."

Jack O'Connor 1963