A 7tcu is a good candidate for rechamber to 7-30. Unfortunately it would probably cost more than a new barrel by the time you were done unless the barrel came cheap. If it did it may have problems, rough bore is one I've seen on a few T/C barrels. Off center chamber is another but the rechamber should fix that if the 'smith is competent. I'd expect a rechamber to be from 50-75 bucks if they have the reamer but the shops vary greatly as to price. I've heard someone say they were quoted $200 for an Encore rechamber but that seems more like an attempt to avoid the job to me.