Below the bottom line SAAMI has added notes referred to as ‘NOTE’, something like, Readers note we have measurements in thousandths of an inch and metric measurements.
Then there is HEADSPACE DIMENSIONS, as in: Readers we use the circle with an x in the center to bring your attention to ‘headspace’.
Omitted from your post of ‘Cartridge and Chamber’ is the chamber drawing, omitted from your cartridge drawing is a mention of headspace, and, NOTE they as in SAAMI made no reference to head space as in referring to a circle around an x referring to head space and the cartridge.
Can not be an a mistake, they were consistent, I do not assume ‘it’ is there. Again, it can not be that complicated, I want to know the length of the chamber from the shoulder/datum to the face of the bolt and I want to know the length of the case from the shoulder/datum of the case to the case head, A – B = C when C represents the difference in length between the chamber from the usual places and the length of the case from the usual places.
2.048” Minimum 2.058 Maximum as in note, we did not have enough room to etc.,etc., so we used a symbol to note head space, again, absent in cartridge drawings.
I want to know the length of the chamber from the shoulder/datum to the face of the bolt in thousandths, everything after that is about transfers, standards and verifying, the humble feeler gage can be used to transfer, it can be used as a standard and it can be used to verify.