You may want to think about something like a .300 Weatherby or .300 Win Mag. The .308 certainly has 600 yard range and good accuracy but may be marginal for elk and moose, particularly at longer ranges. As always bullet placement is critical.
1. I like to target practice at long distances.
2. I want to shoot larger game, but not at 600 yards--150 yards at the most.
But I want one rifle that can serve two purposes.