Hey Budman, I know that this is a little spotty, but it's a start:
I'm shooting a 6.5-300 Weatherby, which is very similar. I used to use a lot of H-870, a good performer that accurately drives 140s to 3,400, but ferociously fouling and now discontinued.
Even though data is shown at AR for 85 grain bullets, I'd not waste the time. Besides their extremely lame BC/SD, I smoked every one I tried - blew up at the muzzle, they don't do well beyond 4,200 fps. . .
I've had very good results with Sierra 140 MKs, 142 SMKs, Berger 140 VLDs and Lapua Scenars in 139 & 123 grain weights. Nosler 120 BTs are quite accurate up close, but really tank at ranges longer than about 700-800 yards - their published BC isn't right . . .
I've had excellent accuracy with Retumbo, easily driving the Lapua 123 Scenars at 3,450, but it is a little fast for the 140/142 range in my gun. I can only get about 3,175 with a 140 before showing excessive pressures - not good compared to what I know it will do with the right powder.
I am using Fed 210M primers with Retumbo. I used to use Fed 215M, but found that my extreme spreads were half that with the 210s. IIRC, I had to add another grain of powder to get the velocity back when going to "regular" primers. WLR might be a good candidate, slightly hotter than most regulars, but not quite a "magnum" brisiance.
My next powder to try in it will be H-50BMG. I had tried H-5010 some time ago, but it seemed no better than H-870 for velocities and H-870 was still in production, so I stuck with it. Now, I believe 5010 is also discontinued.
Do you know your case's water capacity? If it's reasonably close to mine, I will give you some charge weights that worked well for me.