Bipod and bag. I can usually shoot a nice .3-.4 group but anything at .5 I'm always happy. That's obviously after everything has been tweaked.
Or once in a blue moonReminds me of the guys at the range that shoot at night for "perfect" conditions I guess I better start
I think you could get there if you put a tight neck into your next barrel once you've shot-out your current. My .300-caliber target rifle had 0.001" total neck clearance. When the bullet is straight-on with the axis of the bore, it will do less banging and bouncing around on its way to the muzzle. I really do think that's why I was able to shoot a few groups in the .200" to .300" range...I don't and haven't shoot in the 2's.... Ever.