[stagpanther]

Thanx Nathan--HiBC I believe already nailed it, what I found measuring the cases--though not exactly definitive, is that there is likely a differential in the two chambers in shoulder cuts which, when allowances are "stacked" can account for the differences I'm seeing in case expansion between the model 70 and the vanguard. I also cleaned several cases and examined from within with a borescope and saw no signs of unusual flow or an area of incipient weakness, and considering the user only fires factory ammo one time, I contacted them and--after eating some crow--told them it was a false alarm but that 1) I wanted to measure the rifle when the complete set of PTG gauges come in (I've used most of them, but PTG's are the best IMO); and 2) if they experience any unusual difficulties feeding or extracting factory ammo to discontinue use and let me know.