I have been reloading 454 for a while and I can't remember ever seeing load data for that light of a bullet. Of course, I have never looked either. I would guess that you will have a hard time finding that. You are basically describing loading TC/Ruger 45LC loads. Since a 180 or 185 gr bullet traveling around 1200 FPS is hot loaded 45LC or 44mag levels, you might just want to load 45s and shoot them out of your 454 for the specs you are looking for.
As a side note, aren't those Hornady XTP at that weight meant for 45ACP?