My load for two Ruger .45 colt Vaqueros is 26 grains of H110 over a 250 cast. H110 will give you better velocities with same pressure loads.
Just something to try if you want to experiment. As a note, these loads are only recommended for Ruger single actions based on the blackhawk frame, but I would think that the super red hawk would handle them well enough.
Good luck!