hci, you can only get an answer from a wildcat type reloader or from someone that forms cases, basic reloaders only have an ability to make fractional adjustments as in 1/1 turn of the die = 1 inch or 1.000, 1/8 of a turn of the die = .0071429, 1/4 turn of the die =.0142857 etc., and with no way to confirm/validate the fractional adjustment they are just making guesstimates.
And the only method they have to move a shoulder forward is to fire the case, a case that is formed first then fired is a fired case, not a fire formed case, or I could say I form cases first then fire. Back to the .001 thousands. I determine head space first, as with my Eddystone M1917 with .016 thousands head space, it is believed something bad will happen if a rifle is fired with .016 head space, over and over on the forums it is repeated that Hatcher reamed a 30/06 chamber by moving the shoulder forward .125 thousands and was amazed the case did not have incipient case head separation, today wildcatters and case formers call that firing an 8mm57 in an 8mm06 chamber by mistake, nothing falls off and all you will get is a very short neck 8mm06 case, the same when a 308W is fired in a 30/06 chamber, nothing falls off and you get a .400+/06 case (a 308 case without a neck or shoulder.
By determining head space first (length of chamber from the face of the bolt to the the shoulder of the chamber) I can adjust the die to the shell holder in thousands with the use of the companion to the press tool, the feeler gage. Instead of firing a case to move the shoulder forward, I find cases that are longer from the head of the case to its shoulder than cases used in my chamber as with the 280 Remington when compared to the 30/06, the 280 shoulder is forward of the 30/06 shoulder by .051 thousands, by being able to adjust the gap between the die and shell holder I can form cases that fit my Eddystone with .000 head space, I prefer .002 thousands, I have a unique press, when the die is adjusted down to the shell holder cases sized in it come out after sizing as FULL LENGTH SIZED or MINIMUM LENGTH CASES or the same as commercially sized cases, or cases that are .005 shorter from the head of the case ti it's shoulder than the SAMMY sized chamber by .005, if this is not obtainable, I want my money back. The allusive part is the SAMMY chamber, that is the reason I determine head space first because the SAMMY chamber is rare, the only SAMMY chamber I have are the ones I have are the ones I cut, and those are always short.
If you are sizing it means you have fired, what you do not want to do is move the shoulder back (much) if I had a SAMMY chamber and was sizing for it I would be happy with setting the shoulder back .001 thousands, this is not possible with a fraction turn of the die, a 1/64 of a turn is .0008929, then there is the part that is impassible to get over to a reloader, the fractional turn adjust men can be verified with the companion tool to the press, THE FEELER GAGE, imposable to understand why someone would guess the adjust men by fractional adjustment when they could go straight to the feeler gage, select a leaf and adjust the die. So for a .001 adjustment I would use the .004 thousands leaf and make the adjustment on a SAMMY chamber, again I do not take their word for it, I make gages to determine head space, I make tools to determine the effect the chamber had on a case when it was fired.
Cases that are too long because of being fired in non SAMMY chambers have a shoulder forward of the standard case, I purchase cases at the range for from .008 to .011 cents each, I do not need the cases, I need the cases that are too long from the head of the case to it's shoulder than the perfect minimum length case AND I know new cases are full length sized, again I want to know the length of the chamber in order to adjust the die to the shell holder.
F. Guffey