We will start over, the shell holder is .125 thousands deep or .125 thousands from the deck of the shell holder to the top, if it is not the company that manufactured it will replace it. When a case is placed in the shell holder and the ram is raised the case is sized when pushed in to the die, the distance from the deck of the shell holder to the shoulder of the die is equivalent to full length sizing or sizing a case to minimum length from the head of the case to the shoulder, when compared to a go-gage length chamber the length of the case from the head of the case to its shoulder is .005 thousands shorter than the length of the 'go-gage' size chamber .005, this makes the perfect case length .000 and the chamber length +.005 if gages and transfers are used and understood. So, if the deck height of the shell holder is .125, that is all it can do.
The die can not grow, there have been a few well meaning hand loaders that have ground the bottom of the die to shorten the distance between the deck height of the shell holder to the shoulder in the die, anything that be accomplished by defeating the design by grinding can be accomplished with a feeler gage 'in thousands' and grinding compromises the integrity of the die and or shell holder, hand loaders can not say 'feeler gage' and the concept of using a transfer escapes them, forget making gages and transfers.
Sizing the neck, when the neck is sized the neck gets longer, when the ram is lowered and the sizer ball is pulled through the neck expands, when the neck expands it gets shorter, unless the inside of the neck is dry and the case is work hardened there is little effort required to pull the sizer ball through the neck, the belief the case gets longer when the sizer ball is pulled through is perpetuated by those that assume it happens but never measure cases before, during and after.
Changes is shoulder position, I only have one name for a sizer die and that is 'full length sizer die' but I do have a lot of fancy uses for the full length sizer die such as neck sizer, partial neck sizer, neck sizer with partial case length sizing and full length sizing with case support and with the aid of a feeler gage I size cases that are .017 thousands shorter from the head of the case to the shoulder than a go-gage length sized chamber to infinity, or a practical .011 beyond a go gage length chamber.
Sizing without a standard, after sizing the first case is chambered, it should chamber, then a bullet should be seated (without primer/powder) and feed through the magazine, it should feed, if it does not chamber there has to be something wrong with the bullet seating process, but if we did not measure the case diameter at the shoulder after sizing we will never know if the shoulder expanded and started to collapse when the bullet was seated, seating should be effortless, so effortless the manufactures did not build case support into the seater die.
I used a box of 20 new/unfired Remington 30/06 cartridges to measure the effect each case had on head space, + or -, the effect was .0025 or .00125 either side of .000, good control considering they are loading for a chamber that, in the perfect world, is .005, when I size a case I am looking for .004 IF THE CHAMBER IS THE PERFECT CHAMBER, again, I have one chamber that is +.016, I can not accomplish this as a target by smidgen adjustments or with washers, I simply adjust the gap between the top of the shell holder and bottom of the die with a feeler gage in any number of old presses that are stronger than the case being sized, AND effort and full length sizing increase when the number gets close to .000 or minimum length sizing, all the effort is at the end of the stroke.
Sizing the case and the effect sizing has on the position of the shoulder, first the neck gets sized then the body of the case starts to get sized, when this happens the shoulder is pushed forward, then the shoulder gets sized, this is the reason I like the versatility of the full length sizer die, it neck sizes with partial body support, with a feeler gage the effect the case length has on head space can be controlled, the feeler gage works better than a 'tad' or 'smidgen'.
F. Guffey