Check alliant and Hodgdon sites?
Worst case Under " Good .300WM loads" I posted a plot of quickload data barrel times.
It shows how sawtoothed adjacent "burn rate" powders might (depending on quicksand algorithm) be.
There is a hole inn the data for Imr-4350-H-4350 but A4350 is there. It might give you a feel for what powders may be similar to what you are looking for.
