If I give you an answer will you stop ed?

Wall thickness recommendations can reliably be made based on the measurement a large sample of unmolested barrels; for my purpose vintage pattern welded and fluid steel. That data has been posted.

Recommendations for vintage shotguns are however dependent on:
The tensile strength of the steel used to fabricate the barrel
The presence of pits as determined by visualization with a bore scope or camera. Mechanical gauges are unable to measure the thickness at the bottom of pits; I would be very interested if the current ultrasonic devices can do so.
The pressure of the load the shooter intends to use

SO examiners must individualize their advice. Simple minds want simple answers ed but it's not that easy.