I had an Omega, briefly, that I never fired but did some extensive research about. A 1:20 barrel ain't gonna shoot worth a dang with PRB (except with light loads up to, maybe, 50 yards). You have to use Minies, sabots, or something like the power belts. There's a modern muzzle loading forum that might be of more help to you--lots of different loads, etc. Here, the TRADITIONAL muzzle loading forum is going to have more information on the more traditional rifles--which are mostly 1:40 and slower.