42.5-43 in heavy brass, 43-43.5 in light brass, 2.78-2.8 COAL should give you around 2600fps (it is between 2450-2480 for me depending temperature and brass type out of an 18").
I just copied Rob's pet load with the A-Max and Varget and it works under MOA all day long for me. But if your reloading go out and do some testing and find what works in your rifle.