While round balls can be shot for plinking in inline muzzleloaders, forget them for hunting...
I have 2 custom flintlocks and a barrel made for round balls has a slower twist and deeper rifling than modern inlines...
You need to find the proper combination of bullet and sabot for best loading and grouping...
T/Cs are known to have tighter bores than say a Knight...You might try some Crush Rib sabots...
With inlines plan to clean between shots, forget having to take a 2nd shot...I can shoot multiple shots with my flinters but it's because I load the 1st shot with a .018 patch and the 2nd with a .015 patch...
When sighting in an inline I run 2-3 damp patches (both sides) with rubbing alcohol, then a dry patch followed by a slightly oiled patch and another clean, dry patch before I load...
When hunting these supplies can be carried in a zip lock bag and within 3-4 minutes you are ready to shoot again...
PowerBelts aren't the best bullet for hunting...There are better bullets that do more damage with reliable exits once they get to a deer and they don't have the ballistic coefficient to shoot as flat as say a SST...
Finally...Go to 2 pellets...Or better yet, go to a granular powder so you can measure each shot because with muzzleloading you are handloading each shot...To find the most accurate load, granular is the way to go, it's also cheaper...I prefer real black powder (Goex FFF) pr Pyrodex R-S...Anywhere from 80-120grs is plenty for deer hunting...