.440 ball, 50 grains FFFG or Pyrodex, and lubed .015 or.018 patch.
Works for me a T/C Seneca, same twist, should shoot similar.
Now I will be “flamed” for mentioning the P word.
Good luck
70 to 80 grains of pyrodex rs or ffg american pioneer. I use either a .440 rb with .018 patch or .445 rb with a .010 patch shooting at 100 yard target.
In my .45s anywhere from 60 grains of 3F to 70 grns of 3F (black) makes a nice accurate load and a fine load for deer. On the low side 30 to 40 grains of 3F works great for prb.
60 grains of whatever powder (real black, sub, 3f or 2f, I prefer 3f) for general purpose shooting and deer, and 30 grains or so for squirrels and bunnies. I am assuming it is a percussion, if flint use only real black.
I generally shoot 50 grains of 3f black powder in my .45, which is admittedly a light load for hunting, but it is accurate enough and kills milk jugs just fine. you can probably take it up to 70 grains with no real issues, but you probably want to consult the manufacturer's manual and load recommendations if you want to go upwards of 90 grains. No real reason to do that, but some folks like to make lots of smoke.