Bart B., I was told typing slow was rude, or I should say telling someone no matter how slow I type when I hit the post button all of it comes out at the same speed.
Shouting is also rude, telling someone “What you do not understand is etc.., etc..” is rude.
I do not know how to tell you all of that information you posted is not necessary, in the book written by R. Lee about modern reloading is all the information that is necessary/nice to know.
You went to the trouble to furnish information regarding a link, omitted is the price of the tool they make, again, the tool is not necessary.
. “I've not found anyplace that states what headspace should be relative to that”, again, the information is not necessary, this stuff does not run me into the curb, none of this stuff lock me up, I can thumb to the back of the R. Lee’s book on modern reloading to page 703, write down one dimension then say “Mr. Lee, thank you, thank you very very much”, even that effort is not necessary. (effort: thumbing to page #703)
Many years ago in Internet time I got the impression reloadrs/smiths/ shooters thought gages came from Mars and made by Martins. I did not agree, I am not a Martin I am a people, I make gages, again, when the bolt closes the chamber gets dark for most, it should not be that way, or it does not have to be that way.
The man ask for help, I ask, ‘What is he going to do with the information you posted?”