Check out this compelling argument for .284win (still factory ammo produced) http://www.6mmbr.com/gunweek095.html
I have always loved the .284 Winchester. I still shoot my original lever action, and I built a custom bolt gun a few years ago. You can really coax a lot more out of this caliber if you handload though. I consider this the 'original short mag'

6.5 Creedmoor also sounds good for you with good factory ammo selections.