There could be differences in throating, etc. However, in checking my Hornady #9, there was no clear trend. Some loads were almost equal, some a bit heavier for one or the other cartridge. The biggest differences seemed to be for the 225 gr loads. As usual, I check different manuals and in this case both sets of Hornady data, and then start a bit low, watching the expansion at the pressure ring carefully as I work up to max.
