For a long time my state required patched round ball and I found that the keys were a very tight patch fit and a moderate powder charge. I tink that heavy charges caused the ball to strip the rifling.
When NY lifted the PR reguirement I switched to one of the lighter weight TC maxi hunters with very good results.
I wish I could give you exact load data but this was 20 years ago. I mostly shot Pyrodex RS although I did briefly expriment with some 2F Goex.
I did shoot 3-4 deer with the round balls, but I have two that I recovered. They were ok deer killers but not really optimum as I don't think they penatrate that well, but good enough.
The Maxi Hunters I used for several seasons until inlines became legal and I switched again. They were always thu and thu even on shoulder shots, Only bad thing was a touch more recoil. In my btwo TC's ( a new englander and a 54 cal renagade) I could shoot some heavy podwer charges behind the maxi's with good accuracy.
If it were me I would start with the maxi hunters, as they have less variables.. basically just powder charge.
For patched round balls, I would choose one size of roundball and try two thickness of patches. . I ended up using the TC natural wonder lube though YMMV. Between powder charges, patch thickness (and different lubes if you so choose) there are many many variables to play with with a round ball. When you add in how long it takes to load/shoot/clean the muzzleloader you can spend some serious range time, which can be good or not depending on your goals.
best of luck
