Thanks Dean,
That is exactly what I was looking for. I know what the old literature says about minimum safe wall thickness 6" from the breech--about .090 but I can only speculate that guns with .040 to .050 might be safe to shoot as well with low pressure loads. I will measure my other two pattern welded barrels and post those numbers tonight.
Thanks for all the others comments as well. I am hoping more people will post their measurments so we can see what difference between guns and gauges are.