Re: 300 wsm vs 308 for long range shooting
You certainly can accomplish your goal with both. 308 will be cheaper and you have a wider selection of brass, etc. However, 308 just isnt a great round past 800 or so. Yes, we all shoot it that far (and some people farther). I love my 308, but it would not be my first choice for shots at 1k....not even close. So, if most of your shooting is 600-800 I would say the 308 will do wonderfully with little recoil and (relatively) cheap components. It will be harder to shoot at 1k compared to other rounds, so you will have to be that much better at reading wind, etc. 300wsm will offer a little more room for error in windage and open up some more hunting options in larger game, but at a trade off of increased recoil, more expensive components, shorter barrel life, and loss of some magazine capacity (for AICS mags).
My initial thought is buy a 308....shoot the hell out of it, learn to read wind, and have fun. But its a tool, so pick the one which best fits your intended job.
Sean