Some years ago I had a friend in Houston who did the same with a .375 H&H maggie, his squirrel load was a .375 round ball...what the heck, it worked...but back to muzzleloading.
I never actually chronographed my loads in a Cherokee but Sam Fadala did for his extensive work "Black Powder Loading Manual". At a 70 degree temp. he recorded:
10 grains FFFg-1120fps
20 grains FFFg-1649fps
30 grains FFFg-1871fps
40 grains FFFg-1919fps
50 grains FFFg-2016fps
His conclusion, which paralleled my own accuracy results, were 20 grains for the most accurate, 30 grains for the optimum small game load and 40 grains for tougher game like turkey or larger predators. He noted the 50 grain load as not sufficiently accurate, I agree, finding the groups rather enlarged over the 30 or 40 grain loads. The little 10 grain load was fun to shoot, reasonably quiet and sufficient for squirrel & rabbit(700 shots per pound of powder is a plus)...Ma Williams churned out some excellent hassenpfeffer with the results!
The .32 & .36 caliber Cherokee and Seneca use the 1-30" twist rate for these small bores as a compromise to stabilize these small balls at reduced velocity. Other commercial and custom made .32's use slower twist rates and give better accuracy results at faster velocity. TC also intended the faster twist to stabilize the small Maxi ball rounds they made for these guns. These slugs allowed the small bore shooter to 'up' their game for the larger game and predators, namely turkey, javelina, fox or coyote. I don't consider either as sufficient for deer but it has been done. They are small game tools and should be used as such. They are light and handy, excellent guns for their intended function. Good luck and good shooting.