John may have a point on the smaller cals, although i don't think its enough to worry about. Guess it depends on the person, weight didn't bother me to carry. And if for field carry or bench shooting when hunting. A 270 ought to do just fine and not be anymore to carry than a bolt rifle, same with a 22-250 IMO. As he said, a Contender 21" 223 for carry would be nicer than on an Encore maybe, but still a personal thing. If you hunt anything off a portable bench, etc the weight won't be as much of an issue though.
Barrel choice is going to come down to your uses... what you hunt, how you hunt, how far you shoot, but the sky is the limit for choices if you also consider custom barrels.
YMMV