If you want a light rifle that shoots under 1/2" out you can't beat Ultra Light Arms. Melvin Forbes builds absolutely top quality rifles for a pretty reasonable price.
Of all the high end and custom light weight rifles I have hunted with and owned this is my favourite custom. I only wish I had found these when I was twenty years old. I would have bought a couple of different left hand calibers and probably never bothered owning anything else. It is my go to gun since I bought one ten years ago. The rest of the closest of big game rifles hardly ever gets out for a walk any more.
http://newultralightarms.com/?page_id=10