Sonic Vs Mechanical Wall Thickness Gauge

[Drew Hause]

I appreciate Edgar's insight. Some of you are likely following this thread
http://www.doublegunshop.com/forums/...=357105&page=1

I believe we're going to end up with a cascade of options for non-destructive (duh ) testing of vintage barrels; fluid steel or pattern welded, starting with external and internal (via a digital bore scope) visual examination.

The problem with pin and micrometer wall thickness gauges is when pits are present. It is very difficult to position the pin exactly in the bottom of visually identified pits, and impossible if the pits are on the medial wall.
I hope to have the results of radiography on a second barrel tomorrow. This is a negative x-ray image of the first, which enhances the defects in the barrel wall, and may also be useful for measuring wall thickness



Stay tuned.

[Eldon Goddard]

I should have given more information in my original post. If you look at precision ultra sonic wall thinkness gauges. you will see they can measure in the range we need. For example the TI-007 Precision ultra sonic wall thinkness gauge has a measurable range from .006'' to 1'' with a resolution of .001''. However if you read the manual you will see that the minimum radius for convex surfaces measured is .5'' or a little larger than a 4 bore. or 2.5'' for a concave surface. So even a 1900 dollar wall thickness gauge can not measure a barrel smaller than 4 bore.