If forced to pick "1" powder for my uses it would be IMR-4064.
Works well in 22-250, 243, 6mm, 257 Roberts, 270 with 110 grain bullets and 30-06 with 150s. Wasn't bad the one time I tried it in 223 with 55 grain bullets either.
Maybe not top velocity in those cartridges or top accuracy for a certain load but good enough most times.
My 22-250 loves RL-15 so burning a good amount of that right now.
