RE: Nikon Omega question
Personally I doubt that all rifles will shoot so close that you can depend on the range listed with the scope. I have set mine up with the Burris Ballistic Plex scopes which is similar to the Omega but has cross dots kind of like the omega circles. There is another scope with different size circles that can be used as a range finder but it is way more expensive. I think you will just have to pick what kind of scope you like and shoot your rifle a lot to determine where it will hit with the loads you pick. I think with muzzleloaders there is just too much variation in how we load and shoot to rely on the charts.