Tatume, I know what you're saying, just that I prefer a muzzleloader to look like one, and that for hunting big game, there is nothing better than a round ball, from an adequate bore.

PBR if the rifle has a 48" to 80" twist, it will shoot more accurately with round balls than with conicals. A full calibre elongated bullet is a conical - always was called a conical - except back in the 1850's it was called a conical ball.
For me, the proper charge for a .50 cal round ball gun is 90 to 100gr. of 3f or 120gr. 2F - this is for hunting moose and elk. Deer can be killed easily with a .45 using 55 to 65gr. 3F. For moose and elk, the best hunting calibres, the ones that make them stagger, start at 16 bore and get larger. Anything larger than a 13 bore lacks a flat enough trjectory for easy hitting past about 175yards. It has the power though, if one uses a range finder and express sights.

As to long range accuracy, the last group I shot at 200 yards with my hunting rifle, was 6 shots. Off the bags, I managed a 1 1/2" wide, by 3 1/2" tall group for those 6 shots. Not bad for express sights. Large bores are accurate and powerful.

My bro manages coffee cup sized to 3" groups from his Virginia rifle at 100 meters - offhand. This is respectable shooting in anyone's book. Round ball, of course & open sights.

Even a cheap .50 or .54 Lyman GPR, with proper loads will shoot into 2" at 100 yards with patched round balls, something many modern rifles barely do with scopes.

Shooting accurately with patched round balls has a learning curve. It goes with shooting and hunting with a muzzleloading rifle.