I'm not an opinion type guy....I like the facts....If you're only talking 600 yards, most any 30 cal gun will do fine...Just look for something you can shoot well...If your max distance is 600 yards, don't let folks talk you into any huge calibers. The fact is, that there are many smaller calibers that will fit your application.
On the other hand, if you want to reach out and touch something at say 700 yards plus, I would take a serious look at the 338 edge. The Allen mag is over- kill, but the edge is perfect for long range.
Last summer I let my boys shoot my edge. They all hit the target (with me calling the wind). Even the two 9 year olds hit the mark at 1,000 yards. My 14 year old dropped his first bull elk this year at 940 yards. The edge is great for these kinds of distances.
chow