Bis, We're the same age, so I guess that makes me an old timer too!
For what it's worth, there is a rondezvous event called the Long Gong, contestants start out at a mid range of 100yds or so and start shooting at the gong, usually a good size target like a 36" circular saw blade or a hot water tank or maybe an acetylene tank. Everyone that hits it moves back 50yds or so and takes another shot and so forth....I've seen em shooting at well over 400 yrds and still hit'n albeit a lot less shooters than started out, and this is with round ball only and offhand, no body support. The biggest mistake folks make is messin with their loads, I had 2 loads I used, in my .50 lancaster flinter, 50 grains for target and 95 for huntin, the huntin load(used pine scent borebutter on my patch when huntin, btw) was used for looong targets and I always held color, meaning I always put my front sight on the target, never cover the target buy aiming at something above it. This was done by using a fine sight and a high sight, bury the front sight in the rear for fine and move it up even with the very top of the buckhorn for high, it worked fantastic and won me a lot of shootin contests, some informal, like shootin at a stick floatin in a remote lake a quarter mile out! It was some fun! Back to the minnie, I've read that they were fantastic accurate in the right hands and you're right on about the minnie or conical being a better projectile than a round ball, it's a ballistic fact, the round ball in comparison might as well have a negative BC for the difference! But, ya know, there's something to the blackpowder magic of a round ball hittin a deer out to about 75yds, it flat kills em if shot through the lungs! That soft ball doubles its size and makes a heck of an exit hole, I just love shootin deer with a round ball. I recovered one round ball that I shot with my flinter at a deer trotting past me at about 25yds, the ball went thru the front part of the chest and lodged in its knee on the offside, picture perfect mushroomed flat, almost an inch in diameter. Er .....what were we talkin about?