Find a T/C Renegade and have it cut for .58 cal. In doing so you can get a specific rifling twist. I had a .54 cap barrel cut from a rusted .50 by Bob Hoyt. He cut it 1-60" twist and it was a roundball shooter.
Bobby Hoyt is the man. One of the few if not only left to re rifle or re bore barrels. He took a "tomato stake" TC .50 cal into a .54 real shooter. You can specify your twist too.
