I don't load many full house type loads. Shot some factory 240 grain JSP ammo in my Henry single shot 44. Didn't chrono it though.What is your full house load weight and speed? Jacket of course.
I'd look in a reloading manual for rifle data, with a slower powder (maybe something like H110/ win 296) for where to start for a full house jacketed load. In my manuals, looks to be around 1,600-1,700 FPS for a 240 grain jacketed bullet and mid-high end of recommended charge of 110/296 from a rifle length barrel.