Re: 6.5-06 best powder for 140gr. Bullets
Your 4831 and 7828 are both very good choices.
IMR4831 = 46 gr to start out ... it depends on WHAT 140gr bullet.
IMR7828 = 49.2 to start, again depending on what pill you use. Both of these are upper, but SANE, loads so it might be a good idea to drop about 1gr below and shoot 1 round to look for potential pressure sign just to be safe. Honestly, the 7828 may very well be THE powder for the 140gr pills
I recommend Win. LR. Primers 100% for sure with either of these powders.
Have a good one,