I use slow burning powders in my rifles almost exclusively.
I use 4350, IMR 4831, H 450, IMR 7828, and Surplus 4831 ( I've got nearly 10 #s of it)
I have been stocked up so I haven't tried Rl 22 or 26 yet.
To answer more specifically,
IF, IF worse came to worse , IMR/H 4350 will work across the board for me.
Jerry