The purpose of a Bushnell 6500 is it's wide range of power adjustments. From a low of 4.5 to 30X. If you are not going to be shooting at close range with it, I think it is a waste of money. I think the Bushnell 3200 series and 4200 series are a heck of a good scope for the money. I do think there better ones, but you will pay considerably more for them.
IMHO - I do not shoot at extreme ranges, so I am not going to comment to the power you need, other than I think a lot of people over scope their rifles power wise. If you are going to be set up with a very, very solid rest, high power is not a disadvantage; otherwise I think it is. Good Luck and Good Shooting