You should be pushing about 1600 fps with that roundball, give or take a few fps. If you're 2-3" high at 50 yards, I would guess you to be about right on to 1" low at 100 yards. The only real way to know is to get to a range and shoot.

The danger with guessing is I've seen these roundballs do some strange things. I was shooting my Mountain Stalker CVA 1:48 twist .54 caliber that was dead on at 50 yards. I was shooting 80 grains of 777 2f a wonder wad and a patched roundball. When I backed up to 70 yards, I was still dead on. I never could figure that out.

If you get a chance, try and shoot at 100 yards. I think you should be right in the ball park. At 100 yards I would aim for the center of the kill zone, that way if it drops a little no problem. If it holds true and tight all the better..