You have the advantage; I do not have cases that have head space. My chambers have head space that are measured (in length) from the datum to the bolt face. I understand reloaders have head space everywhere, they have it in the chamber, their cases have head space and tools? All of their tools are head space gages; that puts me at a disadvantage because I have case gages, chamber gages, comparators; I know, there are those that believe I could save a lot of ink when using the computer if I would agree everything has head space and ever gage is a head space gage, I had rather use the ink.
One more time; I fired a round in one of my rifles, the round had .127" clearance between the shoulder of the case and shoulder of the chamber. When I pulled the trigger the round fired. The case did not suffer case head separation, the firing pin did not have to chase the primer when the case took off for the front of the chamber and the shoulder of the case did not move when fired.
Again: I have a 30/06 chamber that is .016" longer than a minimum length/full length sized case or .0011" longer than a go-gage length chamber, if I fire a minimum length/full length sized round in that chamber the shoulder does not move even though the chamber is .016" longer than a full length sized, new over the counter, factory round. I form cases for that chamber, I form 280 Remington cases to 30/06, when I fire cases in that chamber the round has .002" clearance. I can not miss(?), the 280 Remington case is .051" longer from the datum to the case head than the 30/06 case.
F. Guffey