Doesn't matter if they will fire held by the extractor. That's not headspace.
"... I guess every loading book on the shelf, reamer makers like Clymer, and all the Gunsmiths in the US are wrong then? ..."
I don't see an answer to this question. Are you saying that these people have it wrong and have perpetuated a myth for ... how many years? I'll change my supposition statement to read "... most Gunsmiths ..." or " all
reputable Gunsmiths ...". When did the realization come on you that the two points between which you make the measurements for headspace is from the surface of the breechface to the contact surface of the extractor? At what point in your reloading experience did you decide, "Well, these reloading manuals and pistol barrel makers are just wrong."?
This discussion has been held here before. By your definition, a Remington 700 in .30-'06 headspaces on the extractor. You think so? I guess a .308 Winchester round has the same headspace as a .30-'06 Springfield? They both are held against the breech face (bolt face) by the extractor!
Why don't we just take a 10 mm cartridge and just chamber (jam?) it up in a 40 S&W chamber? They both headspace on the extractor with identical dimensions, right? ... Yeah, I thought not.
[This message has been edited by sensop (edited July 08, 2000).]