Read again and note I didn't say the case
was overheated because I can't possibly know that; I did say
it looks overheated; big difference! (Photos can do things like that.)
Therefore your obviously extensive search for supporting evidence to prove me wrong is meaningless a a waste of your no doubt valuable time.
??? Now you try to make a distinction without a difference.
And I say it's virtually impossible to get such constancy in a reloaded case except by chance; it's just not doable for more than two cases in a row. Laupua cases seem to be the best available and even they have too much variation in blank alloys/hardness, wall thickness and annealing to resize many shoulders consistent to a spread of less than a thou! And that is, ipso facto, evidence that us sweating over such precision in shoulder set back isn't especially helpful.)
I don't recall you asking what any of us may be using to measure set back. But, precise measuring skill and feel IS a very demanding part of consistency isn't it?
I use and like both the Precision Case Mics and Hornady's version but
I DON'T kid myself about resizing cases by using chamber headspace gages. Headspace gages are special drop-in tools for gun makers and gunsmiths chambering new barrels to meet SAMMI specifications, they're not working tools for reloaders.
"Headspace gages" are chunks of steel, they obviously should be repeatedly measurable. (After all, what could change on one of them from one day to the next?) We are simply reloaders working with thin brass containers, not with solid steel transfer gages.
Sweating any case shoulder measurement back to SAAMI standards is ONLY important when making factory ammo that may then be safely fired in any SAAMI gaged firearm. If simply duplicating factory ammo was/is the reloader's goal there is little to be gained by hand loading no matter what gages are used. But, I have to wonder what you really think would be the practical value of headspace gages and optical comparators reading 100:1 to a reloader?
Finally (and include yourself) tell us how many reloaders you know of who use such accurate measuring tools as yours. And might you also tell us how many of those people find those measurement tools simplify producing the marvelous finished cases (i.e., holding sized cases to well under .001" tolerances) you say that you achieve?