My recomendation is to refer to a loading manual (or several). I have two rifles in that caliber (my Encore pistol is in .308). I load Varget and 140 gr Nosler Accu-Bonds and they work and shoot great. Unique is too fast and a pistol powder, although there may be cast bullet loads for it. I cannot recomend a recipe here, but ay reloading manual or powder manufacturer sites can give you what you are looking for. The Lyman manual is great btw.