Go check out the Cold Bore Challenge in the long range hunting subforum. 600 yards is no chip shot for most on a cold bore. I missed my first and hit my 2nd. More shooting at different positions and different conditions is the best training. I'd tend to agree with lawnboi. If you're already strapped budget wise, a new rifle isn't going to get you shooting more. Shoot your 30-06 with a bullet it likes. Practice breathing, rifle hold and trigger control with a dummy round or dry firing at home for good technique.For this season, I want to be confident out to 400 with some wind. I don't think it will take too much more shooting to get myself there.
It would be great if I can get to where I could confidently take a 600yd shot if conditions are good. And I really want to get some more experience with wind, since my elk hunting is in Wyoming.
But ideally I won't ever take a first shot past 300 anyway.