Assuming this is the 58 cal version, 35 grs 2Fg or 3Fg I've found is borderline "not fun." Although the Pedersoli replica has a rifled barrel, I've not found much accuracy difference with a bare 0.570" RB and a simple wad to hold it in place, or if I use a patch. I use 20 to 25 grs 3Fg and have fun punching paper.
FWIW, some say the Pedersoli lock geometry causes the flint to strike the frizzen at too high an angle. A better lock design would scrape the flint along the frizzen at a lower angle and provide better flint life.
I've not found flint life a problem, but I find all flints of the correct width are too long, and will not let the frizzen seat correctly on the pan at half-cock ... so I shorten them by grinding material off the back edge with a green wheel (the kind for sharpening carbide tools).