A good report is as much compression as powder charge. I know Ed's work and though you MIGHT be able to get 450 grains of Fg in a powder charge, I find that above about 200 grains you are just blowing powder out the barrel. You are going to want to learn t o make aluminum foil charges, lots of tutorials on here about how.
As for wadding, there are many options, but DON'T use wet paper towels....I find bread or flower totillas works nicely, but you still need to watch the down range area as a wad of compacted bread is still a projectile.