Given the "diversity" of 1911 components floating around,the 110 years of service,and the you tube diy kitchen table armorers...
I would not assume anything regarding 1911 dimensional conformance.
I have both volumes of Kuhnhausen. There are dimension drawings in the books. There are Datums,or landmarks that allow checking "pretty close" enough to determine any major discrepancy. Your calipers ought to be able to check about anything to .002. Generally, with a 1911 if your calipers can tell you the locking lug or underlug seem within .005 of Kunhausen's drawings ....its in the ballpark. Odds are,there is some noise in the measurement
(Hot tip,I use an adjustable parallel to measure breech face to rear face of the rear slide locking lug. Good number to have.)
Your question seems to be about headspace /head clearance in the context of unsupported chamber goose eggs/case failures. Am I right?
Do we pretty much agree at the timing of the pressure curve where case bulging would take place (near peak) the case head is firmly against the breech?(Regardless of headspace/head clearance)
Even extreme out of spec chamber depth would still fully support the case at the case mouth.
The "goose egg" area of non support is generally in the feed ramp area roughly 5 oclock to 7 oclock.
There is most of the chamber that is cylindrical geometry. Where it is cylindrical,the cartridge case is supported.
From the factory,there is a chamfer or bevel at the chamber mouth to facilitate feeding. There is a corner,or chine, at the transition of that chamfer,or throat,to the cylindrical geometry of the chamber.
As the barrel is made,that clean,distinct corner defines where full chamber support ends. Its got nothing to do with headspace.
The well meaning diy 1911 "mechanic" does not understand the 1911,but he has an unlicensed Dremel tool. He does not really like that clean,crisp line.
He's gonna make SHINY,cuz thats gooder. And he's going to "Smooth and blend" Thats where he ruins the barrel. That rounding,smoothing,blending is removing critical chamber support. That edge was where it belongs.
And misguided "polishing the feed ramp" is a good way to ruin the frame.
The headspace might be perfect with the throat and feed ramp ruined.