Lots of good advice so far, and my comment is buy quality - it is well worth it. Someone gave me a "brand x" scope like you find in blister pack on the rack at big stores. I passed it on and bought a Leupold VX-1 3-9x40 for my Ruger American 308. Big improvement. Then I bought a VX-3 for my wife's rifle. Wow. (I did that backwards I think!) You have to see to shoot, and there is a difference. I remember reading that you should spend 2 or 3 times more on the optics than what you spend on the rifle - and now I understand (and agree). Even an old iron sights dude like me can see that.