John,



You need to consider a few more factors;



How far do you expect to shoot ? - the further you expect to shoot, the more power you need (10X is good for most) I use 4X-16X because I live out west.




The objective lense is measured in MM's - the larger the more light gathering ability, but the higher you need to mount the scope.


I'm only 5'6" so I put 44MM scopes on my rifles (happy medium), so I can still use low rings which enables me to maintain a good cheek weld on the stock.



Most importantly, with a 300WSM (magnum round), I would recommend over built rings and bases.


I use Burris's new Zee rings (read why below) and "weaver style" bases (# of good ones out there).


http://www.burrisoptics.com/sigrings1.html#2



I put this set-up on all my rifles including my little .204 (I like things over built, as I said).



All any of us can do is to make the best "informed" decision possible given our individual budgets.