Rick, that is a super nice looking plains rifle!!
Round balls at extended range aren't going to expand/flatten because there isn't much energy left and especially so with smaller bores, blood trails are going to be thin unless you are shooting at a pretty decent down angle and get a low exit. To me extended range is where your load slows down to around 1000 fps. Depending on your load that can be 45-50 yards or closer to 100, round balls have awful BC and slow down fast. My buck last year at 94 didn't have much if any flattening of the ball that I could see in the wound channel, that ball started off at about 1500 in my hunting load drops to 1000 at about 80 and about 960 at 94 yards with a little under 500 ft/lb of energy when it gets there. A 300 fps increase at the muzzle would only net at 100 fps at 94 yards and about 90 ft/lb. A 62 at the same 1500 at the muzzle will be a hair faster at 94 yards at around 1000 fps but energy will be around 800, nearly 40% more. With patched round balls bigger is definitely better, and more so as the range extends. Shooting deer at 80+ with a 45 or 50 cal isn't much different than shooting them close with a 9mm or 40 and ball ammo, results will be similar. Cut that distance in half and the 45 or 50 will kill quite well.
I don't hunt with a round ball and a patch because there isn't anything 'better'. I hunt with a PRB because I want my primitive hunt to be a primitive hunt, for the same reason I use real black powder and a flintlock to launch my PRB.
