I tried 73.5 grains of IMR 7828 to push a 200 grain Sierra HPBT from my 300 Win Mag today. ( Fed 215M primer) WW Vrigin brass.
It averaged 2,854 fps with a spread of around 15 fps. But the necks were dirty and it only gave me a 1.1 inch group at 100 yards. I may need to push it a tad faster to tighten up the groups. If this powder will work at all in this 26 inch barreled Remington M-700 tactical.