The term I'd use when at Nesika was "GO +.001" or .002". . . (what ever it ended up at)
If accuracy (among other reasons for eliminating ANY extra head space)) is top priority, wouldn't "GO + .000" be the most desirable result that could possibly be achieved, while still remaining within the sammi spec?
I already know the answer to that would be "yes". If all of your guns came up to that exact number, I suppose that would put you in the position of being completely "golden".
BEYOND SAAMI: Now this does stray a bit over-the-line, as far as the topic (as well as the spec) goes, but since the goal of the sammi spec is to assure universal interchangeability within a specific round, I am considering going out-of-spec on my next build.
The scenario is that there are only 2 manufacturers of the brass, including factory loaded ammo. The firearm will be expected to chamber ONLY fresh brass (including factory loaded), and brass that has been fired out of itself. But whether or not it will chamber brass that has been fired (and thereby stretched) out of another gun, is a "don't really give a ****" situation, because it is a situation that is planned on being avoided. In that respect, you can consider it to be a "custom" build.
With that in mind, my plan is to purchase at 50 rounds of each man's new brass, and set HS for +.000 on the longest case found, among the 100 purchased. That will likely put the HS at a "GO - .00x" number, meaning it would be outside of the sammi spec. Now I know that anyone's first thought (including my own) when they hear "out of spec", is "no good". But, the OOS would be on the "good" side. Among the many advantages I see, would be highest possible accuracy attainable, absolute minimal stretching of the brass, best possible gas seal, etc. And the ONLY disadvantage (that I can think of) would be that brass fired out of other guns MAY be too tight. But like already said, that is a non-issue for me.
Now granted, if I was "smithing" a gun for somebody else, or the public in general, I would NOT stray outside of the SAMMI specs, for obvious liability reasons. Speaking of which, I better also add the disclaimer that "in no way, shape, or form, am I suggesting that anyone else try this (at home, or otherwise).
Now that that's out of way, for the custom situation mentioned, can anyone (preferably experienced smiths), come up with any legitimate reason to avoid setting the HS via the procedure that I have outlined?