Using 500gr Govt bullets, my Springfield Trapdoor will shoot about 3" high at 100 on the first shot out of a clean cold barrel. Doesnt work down to center until the 3rd or 4th shot. So, when I hunt, I just hold low for the first and killing shot.
No problem, it is just knowing your gun.
My .53 Hawken is usually right on using PRB.
Bill