I have a 91/30 with all matching numbers, and a Frankenmosin Type 53 in M1944 stock made of the best parts of four different rifles (but with tight head space between the bolthead and barrel).
"some do shoot good mine will keep 2" at 100 yards just 12" high need a taller front sight "
My groups are a bit larger but that's my fault. They do shoot high with the top of the post aligned with the top of the rear and the standard 100 yard bullseye on top of the post. The Mosin 100 arshin/yard setting is basically aim at belt buckle, hit somewhere on upper thorax between 100 to 500 yards.
For vintage/modern military matches, I put my initials in red magic marker on my target at what should be my aiming point for 100 yards.
I have been experimenting with a "Tennessee elevation" sight picture for 100 yards that involves bisecting the bullseye with the top of the rear sight, with the post at the bottom of the bull near the bottom of the notch.
Others have suggested slipping some thin black plastic tubing over the front sight, then trim to zero. (Personally I prefer to have the post near the center of the front sight hood, and have adjustments to the rear sight.)