You could spend a fortune on factory .308 ammo loaded with premium bullets, trying to find which shoots best in your rifle. Provided you can manage 3 MOA, 3 shot groups, out to 300 yards, from field positions, that is all the accuracy you need. A moose after all is a big target. Regardless of whether they were pushed from a .30/06, a .30/40 Krag, a .300 magnum, a .300 Savage, a .303 Brit, or a .308, traditional .30 caliber 180 gr cup and core bullets impacting at 2400-2500 fps have slain a train load of moose over the years. Unless it is all you can find, I would avoid blue box Federal ammo. This stuff isn't particularly accurate in any .30/06 I've used it in, it struggles to make 3 MOA at 100, and I see no reason why it would be any better in a .308. Still, if that is all you can find, it will kill your moose, but at 300 yards the group might be closer to 4 MOA than it is to 3. That is still a dead broadside moose. Conversely, Winchester 180 gr Power Points, or Remington 180 gr Core-lokts both produce reasonably good accuracy and produce good terminal performance. I think you are better off to purchase 100 rounds of a single brand of ammo and get in some trigger time under practical field conditions, than you are to worry about a difference in accuracy of a half MOA between brand A and brand B, then perhaps by next year you'll want to handload.