Just noted the other guys comment on the 270 WSM. All of the WSMs are great cartridges. I have them all and really enjoy them. As a side note... as much as I love my 300 WSM, when I look at the 7mm WSM it THEORETICALLY should be the better cartridge. BUT... the 7 and 325 WSM have become almost reloader only cartridges. Yes you can still buy, but your going into a store and MAYBE... big maybe that they have any in stock. I just picked up a Browning mountain ti in 7 WSM from a friend because he doesn't reload and can't buy ammo (I have the same gun already in 325 - we bought them at the same time). The 270 WSM is still pretty available but the 300 WSM is still by far the king for availability.
My 270 WSM is Browning White Gold BLR (lever action) and with a ballistic matched scope, rocks at 450 yards are no problem. Only shot a couple of mule deer at 100 and 200 yards with it otherwise.
If your looking at the one gun does it all... you just can't go wrong with the 300 WSM.
Hmmmmm.... based on my own argument... me thinks I need a second 300 WSM but in a Tikka????