The two longest shots I have made with a round ball were both around 200paces proable about 185 or 190 yds.
Made them with a Hawken rifle that is a copy of an original ,it has a 35.5 inch barrel and I was using 130gr of FF black[this was before we ever heard of pyrodex]with a 22 thousands ticking patch and a.535 ball one was a deer got both lungs and he went 10 to 20 yds and folded the other was a black bear in canada again both lungs and he fussed and kicked but never left the spot.Lee