There is an on-going thread over onaccurateshooter.com that started as "what's the average cost for a custom barrel thread, chamber and crown". It evolves, as many threads do, and one of the best post is, "doing your own work is a matter of convenience",, you don't have to wait on a gunsmith. With the costs to 'tool up' these days, you could have many, many rifles custom barreled. And, to be 'in the business', you'd have to do many jobs for paying customers to make it worth your while and to pay out.