Stick powders in a powder thrower are, to me, a bit on the "crunchy" side, so being plus or minus 4-8 granules isn't a surprise. With a RCBS 5-10 scale and powder thrower, I throw under by a couple of tenths and dial it in with a manual trickler as mentioned above. On my 5-10 scale I made a fine sharpie mark at 0.1 gn above and below the " > " on target weight (from "on target", roll the tenths barrel forward and back a tenth to see where it points). Each mark is less than 1/8" away from the " > ". This worked well for me back in the early 80's when I was reloading for 30-06 with IMR 4350. It was good enough for 3/4" groups at 200 with Sierra GameKing bullets. I suspect I could still get that today with H4350.
However, I have an Autotrickler V4 today and have found that one granule of H4350 is ~0.02 gn. I still set the charge below my actual target and use tweezers to add the final couple of granules by hand. Do I really need this level of precision? Probably not, but 40+ years as a chemist has influenced me to be as precise as I can, within budget.