10 grains 700x with a 45gr .312 round ball. Shoots like a .22, fun for the kid to plink with a BIG rifle.
Other than that, I've tried 4895 and blc-2 with success. I'm gravitating towards the BLC-2 because it shoots in just about anything from 223 to 300 win mag, with lower pressures, more powder burnt, and faster speeds than the old 4895 standby.