I found a max load of IMR4831 to be very accurate( less than 1/2" grp) with the 85 gr sierra HPBT game kings.
+1
IMR 4831 and the Sierra 85 gr HPBT gave me my best groups in my Ruger 77 243 I had in high school. The next best powder in that rifle with that bullet was IMR 3031. At that time the only thing available to me were IMR powders. I tried 4064, 4895, and 4350 too, but they didn't group as well in my rifle. I shot a lot of groundhogs and fox with that loading.
