Some days seem to go like that Pluckit. That 240 grain XTP sure seems to have potential. You might try playing around with the charge a bit with that bullet.
But dang, it seems so out of balance to shoot a .429 bullet from a .54 bore. I think I would have to try some .452/300 grain XTPs or Deep Curls, or even some of the larger diameters like .475s or .500s.