For hunting loads, the two best powders for this cartridge, IME, are Reloder 7 and AA1680. Both produce high velocities and very good accuracy. I prefer the 220 Hornady myself, but the 200 Sierra has had good reviews too.
The best accuracy for me has been with IMR4227 and AA5744 with cast bullets, but velocities are relatively low - in the .38-55 range. The RCBS bullets were loaded into the lands and the muzzle tipped up before each shot.