“Why do you not set the head space on the go gauge only? AGI recommends using tape to give the head space 0.002 to 0.004 inch excess over the go gauge.
“I appreciate your response. I don't understand it but I do appreciate it none the less”
No one has a responsibility and or is obligated to make an attempt to try to understand.
You mentioned AGI, on the outside chance there are some reading through this form that have no clue what AGI stands for and again (on the outside chance you are talking about American Gunsmithing Institute), I posted a link.
As to their recommendation to add tape to the rear of the gage to lengthen the gage, .002 to .004, makes no sense, the go-gage is longer from the head of the gage to the shoulder of the gage than the minimum length case, meaning if we are talking about a 30/06 a go-gage length chamber presents a head space of .005 to the minimum length/full length sized case. If we are talking about (for example) the 30/06, adding .004 thousands to the length of the gage when reaming the chamber, the added .004 would results in a chamber, when measured. would be a no go-gage length chamber.
Again, I do not use head space gages, I do not shoot head space gages. Wilson Barrel Co. provides instruction, what happens when a AGI educated smith receives a barrel and instruction from Wilson and finds Wilson gives two choices, neither agrees with the institute of gunsmithing.
The AGI also says check often, no one knows where the are or how far they have to go to finish the chamber, it is possible to know, in thousands, the length of the chamber even if it is a short chamber (and we all? know a go-gage will not chamber/allow the bolt to close in a short chamber unless it is the same length as a minimum length case), and I say there is no excuse for not knowing the length of the chamber from start to finish, they give the smith an excuse with their ‘qualifying statement “NO ONE KNOWS”, that makes me want to break into “WHO KNOWS WHAT EVIL LURKS IN THE MIND etc..), we all know the answer, the shadow do.
Thanks for asking?