It would probably add around 1 pound or so. Your biggest accuracy improvement would probably be from a free-float forend, not changing the barrel, although the heavier barrel will probably provide some benefit. Really it depends on your use - if you sit at a bench and shoot paper or varmints, it may be a good swap. If you have much plan to carry the rifle or use it in any kind of action shooting (3-gun, ACTS, etc.) then the lighter barrel is probably better.