I second the matchgrademachine.com advice. They turn out incredible barrels at good prices and in a reasonable time frame.
Also, you can't take a .257 Roberts and have it properly chambered to .257 AI in an Encore. In a bolt rifle, that's no problem as the barrel can be set back. But in the Encore, the headspace won't be true to .257 AI specs. Granted, a seasoned loader can deal with this, but it may cause a problem if/when you want to sell it.
There's one particular 'smith who's moved around the country a bit lately and keeps doing this. He'll take a 30-30 Contender barrel and run an AI reamer into it. Folks -- even other 'smiths -- have tried to tell him otherwise, but to each his own...
Any time I see a TC rechamber listed, I make certain I know what the original chamber was before even thinking about buying it.