Depends on your total MOA available in your scope and how far you want to shoot.
From my understanding, generally a 20MOA base is indicated past 600yds (less if shooting flat calibers).
I shoot a 20MOA on my Rem 700 .308 hunting/LR rifle, but that scope also has 75 MOA of travel.
Here is some good info on scope selection:
http://www.snipershide.com/forum/ubb...91#Post1938091
And base selection:
http://www.shootingvoodoo.com/index....ifle__rings_a/
Bookmarks