Sorry to derail the conversation with another question, but here's hoping for a merciful answer.

I need a bore diameter gauge and a wall thickness gauge so I can better understand the state of prospective gun purchases. I hear names like truth gauge and others but no links to buy them, leaving me calling around to find out the order of magnitude of such expenses.

Can someone recommend the most cost affordable 12 bore solution to bore diameter and wall thickness gauges sold turn-key? How about a solution that does 12-28? Anything exist under $200?

Thanks!