Of course, both will do well for most North American game. If you were starting from scratch, you may consider other factors such as the type of
rifle you want, weight & other issues. I have a Win. Mod. 70 custom rifle
in 30-06 AI that takes care of my needs for a light carry rifle of this caliber, (not used often), it will get within about 50-75 fps of the average
300 wsm with favored 180 Gr. bullets, which I favor for this application & I use a Sendero in 300WM for the longer ranges for this caliber, because it has a 26" & throated to take advantage of that Rem. Magnum length action, it will push a 200 Gr. Accubonds to 3,000fps, a short action 300 WSM with the normal 24" just can't get there. To boot, I would be lucky to
find a WSM or another 300WM for that matter that will group like this rifle
at long range, therefore I have no application or use for a 300WSM whatsoever, but it is a decent cartridge. Sorry, gun writers, that's the way
it is. But again, it would be ok for a first 300mag, no doubt.
I like the 270WSM though, because it gives me more than I can get out of a 270, a great round in it's own right.