As you probably already know, generally speaking, the heavier the barrel the more consistant it will be. The key here is finding the balance between weight and consistancy. Although my carry rifle is 'only' a 280, the build and and barrel contour will give you some idea of the weight you might be carrying.
My 280 - Updated!
The barrel is a Hart #4 Douglas taper. It is .650 at the muzzle. If you went up one contour to a #5 it would be .700 at the muzzle. A 'sporter' contour that is .700 at the muzzle might be a good compromise for your application.