Measuring with micrometer. I understand the relationship of bore-choke size. But if the chokes are constricted to the proper dimension relative to bore size why the wide discrepancies in pattern, one loose, one tight, relative to what they should produce with pretty much all "standard" loads?
How many patterns per set of parameters are you shooting? What method of analysis are you using? Do you have a copy of Dr. Andrew Jones' recent book on patterning? I suspect you are shooting too few patterns and that your analysis is insufficient. Shotgun patterns are way variable.
