I'd start out with 70gr of Pyrodex under a thin prelubed patch with a .490 Pb roundball. I say a thin patch like .010 because some Pedersoli rifles are tight bored and can be hard to start the ball down the bore. Get yourself a ball starter to help.
You absolutely must push the patched ball all the way down to the powder for safety. Make it easy on yourself until you get a feel for your rifle and what it likes for patch thickness. You can ram a ball with a thin patch where you can't with one too thick. The range is not the place to learn this.