RRA National Match rifle should do it. You don't even need a scope.
Their varmint rifles should do it too.
A white oak match rifle or varmint rilfe upper will do it for sure, and you can get that in chamberings that will be more competitive at 500yds.
You'll probably need to make your own ammo to be really happy with it, since off the shelf match grade ammo is spendy.
At 500 yards, your ability to call the wind will make a bigger difference than the inherent accuracy potential of the rifle. My .30-06 600yd loads will drift an extra 1.5 minutes for every 5mph of wind at 500yds. So, if I think that the wind is at 10mph, and it's really at 15mph, then I'm going to miss by around 8 inches, even if my rifle can hold a 5 inch group at that range.
-J.