I would just get a good load for your 300 WSM and be happy! From everything I've heard it is a great caliber! I have a 300 Weatherby and have always liked the ballistics but for some reason haven't been able to get it to shoot tight groups like I did when I first bought it. I never have gotten tight groups like my 270!
Another thing I found true with my 300 was that I had to clean the barrel after about every 10 shots! My groups started straying and it was either due to a dirty or heated barrel? It is in a Remington action and that may be part of the reason...I've cleaned the heck out of the barrel and there probably is a solution somewhere but I'm sick of messing with it!
I recently decided to try a TC Pro Hunter and just bought a 300 Win barrel for it. They didn't sell it in 300 Weatherby or I likely would have bought that barrel. I had the choice between 30 06, 308, and 300 Win and decided on the 300.
Another option you may want to look at is 7MM Ultra Mag. The ballistics look fantastic! You may have trouble finding shells but if you reload it wouldn't be too bad once you get the brass. To complicate things even more, I have a couple friends that use 300 Ultra Mags for deer and elk and love them.
Anyway, if you are getting tight groups with your 300 WSM I would definitely stick with it. I would think it would be a deer and elk killing machine!