Were I to settle on a powder for both handgun and rifle, I'd have to go with Alliant 2400.
That would allow me to run cast bullets in my big rimmed cartridge rifles like .30-30 and .45-70.
That would be my first choice if I didn't have non-magnum handguns to feed. As it is, it works great in my .480, 30-06's, 8mms, .308s, and .303. Unique works better for me in the 6.5x55- go figure.