To address your question of practical rang. What can you consistently group your round balls into a target the size of the kill zone for the species you are hunting? Now a 2"- 4" group with a flintlock rifle at 100 yds is pretty passable for deer and elk but is that offhand or off a bench? At one hundred yards, what is the momentum of that round ball? Does it have sufficient foot-pounds of energy and momentum to do the job or result in a wound and possibly lost game? Can you do this three times in a row from the clean bore or follow up shots from a dirty bore? Elk are much bigger than deer and generally tougher to put down and that is why .54 is a minimal muzzle loading rifle caliber in Colorado for elk. A minimal ball weight is specified, too.
What about the angle? Are you shooting pretty much horizontal? Do you practice at the angles you might encounter during a hunt? I practice on a club range here in Colorado that is on the side of a rising hill. Angles up and down with max about 184 yards way up hill. Decades ago I took a pronghorn doe at a steep angle with a single, clean heart shot at considerably more than 100 yards. Won't mention actual ranged and paced distance to discourage others from taking long range shots. At the time I had become proficient at hitting steel animals from 25 to 200 yards at a range with a similar slope to the shot I made on the antelope. Shots were mostly offhand. Would not try it again with older eyes. I also practice on a different club range with evel 25, 50, 75 and 100 yard target berms, frames. How I shoot (bow or muzzle loader) in the summer determines the limits I put on myself in the field in the autumn depending on what seasons I draw for. Fifty yards or less for deer, elk and antelope is appropriate for me and Old Lady Hawkens now. .
The issue of ethics comes into play when weighing between "should I if I can or should I pass?" You have you know yourself, your abilities, your quarry and your hunting tools. Shooting paper or steel on a range versus live animals in the field is a whole different "ball" game (pun intended). I prefer as close as possible to ensure a humane, quick harvest and enjoy the challenge of getting close. Do you have access to steel gongs or silhouettes to practice (offhand, kneeling, sittting, prone with/without cross sticks) on after you've sited in off a bench? Is that 2 - 4 inch group load enough to tip over the silhouette? Do you use a range finder to confirm the distance you guesstimate? I take a pair of cross sticks when hunting the sagebrush for pronghorns. Last animal taken with .54 ml was 35 yards over a water hole with cross sticks. One double lung shot put it down for keeps. That it decided to fall and die in the pond rather than on the dry bank wasn't part of the plan but that is a different story.
I use a .530 round ball with fifteen thousandsth cloth patch lubed in bear oil and beeswax, 103 or Gene High lube over 70 grains FFFg. If I need a quick follow up shot Butler Creek quick loaders store the same load, patch ball, combo. I hope I never have to take enough shots to have a hard to load bore but a bullet block with ten thousandsth patch and same .530 ball is carried for such a contingency. With a Bill Large .535 barrel, .60 caliber Getz barrel and .62 caliber mystery barrel for rifles on the drawing board, I am going to go up in my powder charges. Many other hunters would consider 70 grains a little anemic for .54. Loads mentioned in this blog site have to take into consideration where they are being used. Out here in the Far West - Colorado and Neveda included it isn't as humid and bores tend to foul quicker with fewer shots than back East.
