They have been pretty lucky so far. But the decisions come down from Corporate where there are no engineers and my voice is not big enough to reach Corporate. We were sent the $95 special for wall thickness, which does more harm than good. The Hosford is a decent instrument but it's still not checking the wall thickness beneath the ribs. The best of the mechanical measuring devices are still a bit dodgy because of the difficulty controlling the tension on the support rods.

Ultrasonics are used on turbine blades and barrels can suffer a similar abuse, just not as extensive. The Chinese are producing some pretty cheap ultrasonic testers, maybe that will be a future tool for gun barrel wall thickness.