RE: .257 Weatherby Magnum.
I get my highest velocitys with IMR 7828, with excellent accuracy. I am experimenting with Reloader 22 at the moment, and the accuracy is excellent. The velocity has dropped off 200 fps with the re 22, but the groups have tightened up considerably. My buddy is exclusively 7828 with his bee. Hot loads are the norm, as I found that cutting back opens up grouping considerably.