My good friend sells bullets to Weatherby. I was going to ask him about the powder blending. Nah. mtmuleyAs far as Weatherby blending powders, I used to have a Weatherby catalogue that listed their load data in it. I got it around 1985 or so. If I remember correctly, everything was loaded using Norma MRP powder. It listed the actual grain weight of the powder in each of the factory loads, and exclusive use of Federal 215 Primers in their large rifle cases. I lost that catalogue in Katrina along with everything else. I wish I could find another one.