RE: Am I gaining anything??
I will put it this way Dead is dead that Mule Deer or Elk don’t care what you shoot him with.
With that said the 300 WSM or the 300Win Mag will work great for the west I like the 300 WSM the most.
I live in Montana and do a lot of hunting here in Montana and Wyoming and Idaho And I can say this from experience the 30-06 will do the job, but the 300 WSM or the 300Win Mag will do the job a little better when it comes to some of the long range shots you will have to take here in the west in order to get your prize.
But first and for most if you have the itch for a new rifle go get one, and have fun.