On my Ruger 338, I have a Leupold VX3 2.5-8X 36 and love it. Other scopes already mentioned, the Leupold VX3 4.5-14X40 I had on a Ruger 7mm mag and pulled it off recently and put it on a Ruger 300 WM. The 4.5 power on the low end is a little too high for some types of hunting. I have a Leupold VX3 3.5-10X40 on a 270 and really like that too. So a the 2.5 to 3.5 on the low end is what I'd suggest and 10X on the top end. Also, if you plan to hunt any where you might ride horses and need to put your rifle in a scabbard, do not get a big 50mm objective lens scope. They don't fit as well in the scabbard.