As shared, it will depend upon whether you have a British Parker-Hale, an Italian Parker-Hale, an Italian clone, or one of the three levels of Indian model guns or decorators.
In brief and to over generalize...
These are replicas of the Pattern 1861 Artillery Carbine which was the "musketoon" version of the P1853 4th Model rifle-musket not used in the ACW.
The rear sight was calibrated to 600 yards.
That being said, one can work up the optimum load combination of sized Minie ball, and powder charge. Or just go with the military cartridge. And then sight it in for 100 yards. That is a side discussion, as around here, most all deer at taken at about 35-45 yards, so some lads sight in for 50 rather than 100. Shooting a 100 yard sight at 50 has the ball's POI really high. Some lads try to shoot patched round ball rather than Minies. That is a longer discussion as the rifling's rate of twist is not the best for stablizing a round ball. But, at distances under 100 yards it is somewhat not keenly critical -especially under 50.
Some cross-over hunters like the "musketoon" as its 40 inch overall length (24 inch barrel) makes it easier to tote, and go through brush and trees.
There are some disadvantages. Some lads find it harder to shoulder and aim when bundled up bulky in winter clothing. And with a shorter barrel, with its shorter sigth radius, it is easier for an inexperienced and unpracticed shooter to pull a shot off target.
My brothers-in-law prefer the two-banded rifle version for their muzzleloading hunting.
Others' mileage will vary...
In gleichem Schritt und Tritt, Curt Schmidt
Not a real Civil War reenactor, I only portray one on boards and fora.
I do not portray a Civil War soldier, I merely interpret one.