Safety issues aside I look at the economics of it:
1. Barring barrels you already own or bought for next to nothing: a factory barrel serving for the basis of the project will set you back $150-$225.
2. Depending upon the chamber-type and the gunsmith you will generally fork over about $100 plus shipping.
Now you are already into your fixer-upper for around $300. Why not just buy a custom barrel in the first place for a few dollars more where you can specify length, profile, finish, chamber (even throating/tight neck) and get it all made on a precision stress-relieved barrel blank?
True some custom barrels run upwards of $500 but there are makers out there who can deliver for not much more than that $300 mark.
Just my $0.02 worth
