Depending on what you want to hunt.. for deer?. I would personally go with as large a caliber as I could and with as large a powder charge as it can handle. Your Pedersolli I will GUESS will use about 20-30 grains max of powder. You are then going to be shooting a .440 ball. So you are really limited by size of lead projectile and the amount of powder pushing that. Granted if you were 25 yards or in that area, it should work. But you might want to hone up on your tracking skills as well.

Were I to hunt deer, it would be with a .50 calTraditions Buckhunter Pro single shot, or a custom type single shot. I would want it to shoot at least 50 grains of powder and as big a ball as possible. In the case of the .45 caliber a Colt Dragoon, Ruger Revolver, are all able to take larger powder loads. I believe they can handle 50 grains. There problem is many states do not allow them in muzzleloader season as they are not considered a muzzleloader.

I shoot a .44 caliber L. L. Pietta. It shoots 30 grains of APP 3f, and a .451 roundball. It does have some impressive penetration at 25 yards. But I just do not know if I would hunt deer with it. But with the Pedersolli, it would be a exciting hunt. As it would test your stalking or waiting skills to the limit. Id just go to a large horse pistol caliber is all. Lyman makes a .50 caliber Kentucky style. They used to make a .54 caliber but I have not seen them lately.