I have a buddy with a van in 7mag. It is accurate, at least after trigger work. The factory trigger is poor.

Scope power to see 200 yds. It depends on glass quality a nd environmental conditions. If there is a lot of shimmer you will have a tough time. At a range I go to, with there spotters, I can't see a .25 with a 30x but I can with my Leupold 10x. Under proper conditions I can make out the hole at 300 yds.