LOL..!! Thanks, Charlie... I truly appreciate the gracious and crotchety non-endorsement.
Just guessing...but based on a couple of recent less-than-friendly PM's from a certain poster, there may be some deep and dark meaning attached when the term pro-staff was used.
As for the competent gunsmith comment; yes, if he is competent, he would know to set the barrel back. "Competent" is the key word here. The entire AI concept is based on a shorter head space measurement on the AI'd case versus the parent case, no matter what cartridge case is being AI'd. Thus the crush fit when chambering a parent case like Rustydust mentioned.
More than one person has had a chamber AI'd and had fits with cases separation because of who did the work... a not-so-competent gunsmith in all cases who was thought to be competent...
Before leaving the rifle, I'd definitely ask how he was going to do the work. And as mentioned, get the action truing done also while the barrel is off of the action if you want it to shoot well. Money well spent...
-BCB