My benchrest rifle is chambered for 6.5x.284 on a 700 long action. Built by Bobby Hart @ www.rwhart.com
I have a 1 in 8.5 twist and 30" Hart bbl. For a hunting gun I would probabyly go with a 26" tube. I'm using Berger 140gr VLD's over 48.5gr of H4350 (be sure to work up to that starting around 43gr) Federal 210 Gold Medal Match primers and Lapua brass. I'm getting 2950fps.
I have several 10 shot groups under 10" at 1000 yards. Best group so far was 6.8" New dies and a better scale should get me some better groups this year.
Working on some test loads now with 142 Sierra and 144 Lapua's with H4831SC.
If you have any other questions shoot me a PM or give me a call.