You didn't give us a price range but here are some options. If you go under $500, durability and repeatability usually suffer, but Leupold Mark AR and Vortex Viper HS are solid in that price range. The Vortex Viper pst
, Nikon Tactical, Leupold VX3 LR with knobs, SWFA Super Sniper (new models), and the fixed power I.O.R are all great scopes in the $600-$850ish area. A budget above that and I am no help at all. I have used a U.S. Optics 10x which is very good but has weaker glass than my I.O.R 10x. My I.O.R is straight 10x ($800)on a 6.5-284 with 140 VLDs going 2940; with a 200 yd zero I have enough elevation to get to 1500 yds and make 800 to 1000 seem pretty simple. I have a 2.5-10 I.O.R and love it also, the only real drawback is you can't get custom engraved knobs for them. Keep in mind that you will need a high end range finder to keep up with your rig, and that is where the real cost will be. Hope i was of some help.