I think PSA has a room full of gorillas with cheater bars torquing their barrel nuts. You should be fine as long as you never need to swap the barrel or barrel nut.
I tried FedEx and UPS earlier this year. Neither would send it. (UPS said they would if I had my own UPS account.) I ended up using SpotrsWorld. Their rates were decent, relatively speaking.
My limited familiarity is with S&W revolvers.
The angles on the outer edges of the ratchet teeth are key to getting the timing right. They have to be cut correctly for each tooth. It is time consuming and can be nerve-wracking the first couple of times. That being said, it is not beyond...