.40 S&W to 9mm Barrell Conversion?

I don't know about half of nothing about anything, but just for clarity sake, would you need more than just a new barrel? Would there be other parts to check on such as the magazine mouth width, extractor depth, firing pin diameter or recoil spring strength?

Again, not totally sure I know what I'm talking about, just wanted to throw that out there.

I haven't seen one yet. For the price of a Taurus just buy another gun in 9mm or .40.

There is not one available.