I like IMR4064, about 72 grs behind a 400gr Barnes TripleShock for about 2230fps in my 24 inch barrel CZ. Thats good for over 4400 pounds of energy. Not earth shattering but certainly adequate for anything that walks. Other loads do about the same, using both Varget and R15 in the same charge range or a bit more as they are slower. One factory load I had, RWS I think ran over the clock at about 2350, pretty potent stuff. I seemed to get the best velocity with the Barnes bullets over the others, and it shoots better in my rifle than the others.