Don't have a Greener. Do have no-name Webley&Scott. Stuck em with the W/T gauge a few moments ago. Depth of measurement only 1/2" as that's all the knife edge jaws on my dial caliper will reach. Right barrel wall .048"; left .062". Dial caliper says .1" combined thickness of both at pt. of tangency between the ribs. Only -.01" difference from combined walls outbd. to pt. of tangency. May be that the caliper was picking up the exit from muzzle (should have checked to see if there's a parallel section after the choke or straight taper to muzzle exit) and the WT gauge reading deeper in but whatever the case, I'm not getting the big discrepancy you're getting, Dave. Tubes at muzzle appear to meet at pt. of tangency on a circle. No suggestion to my eye of a flat. Does appear counterintuitive; I would have thought external striking after soldering up the ribs would produce precisely the opposite result (combined wall thickness at tangency > than combined wall thickness at a pt. where W/T gauge can be employed).
jack
