What load are you shooting?
One thing I've found that helps when I'm working up loads and trying to shoot groups with a bead front sight is to use a target with a large (at least 12") solid circle. Orange is best if you can find 'em. That way you can center the front bead inside the colored circle out to 100 and get the same hold (or close to it) every time.
I settled on a 348 grain Powerbelt and 80-85 grains BH209 in my T/C Triumph, shoots great. Good luck!
