I'm just starting with PP 45/70 in a Pedersoli Sharps. I've sized .458 soft 545gr Postell bullets to .452 (.002 over bore size) using a LEE sizer. They are then patched with green music ruled printer paper to .462, waxed and loaded into unsized fired cases so they are touching the lands. These sizes match my throat and freebore.
I'm using 25gr 5744 and they seem to shoot ok out to 600yds which is the farthest I've taken them.