Congrats on the new gun!
I have a 300 Win and love the heck out of it.

I'll start by saying, there's a couple of things we need to know to be able to answer your question:
What type of animal are planning on hunting?
Are you buying factories or hand loading?

If you're looking at factory only,I personally loveWinchester Supreme Accubond 180 grainers for everything from deer to elk. My model 70 really loves them.
I hand load for mine and for deer I load 150 grain Nosler Ballistic tips, for my next elk hunt I've loaded some of the 180 Gr. Accubonds and I've also got some Hornady 110 grain V-Max's that I'm going to load and try on some cayotes when I get a chance.