For 200 or 300 yards, 24.5 grains of any suitable powder under your 68 grain bullets will work just fine as you establish your zeros. For 600 yards use one grain less under a 80 grain bullet. Go out and learn. Welcome to the highpower world.
Until you learn the game and can hold hard, it doesn't really matter much what powder or load you use as long as it is safe. You won't shoot clean until you learn to shoot clean.
Shoot a match or two and what I say will make sense.