Measuring rifle chamber ?

[Bassfish1952]

Here is a simple yet somewhat crude means of measuring your headspace setback if you are at all curious. Take an unfired round & place a thickness of scotch tape or masking tape on the base of the case. Load the round with the thickness of tape on the  base in the chamber & close the bolt. Expect this will close with no resistance. Then repeat the process with a second & third layer of tape if needed. Any factory ammo may be a bit inconsistent though this is an inexpensive yet a bit crude way to evaluate your head space. My hope or expectation is there would be no need for the third layer of tape as the second layer offered resistance to closing the bolt.

I have the gauges to test this headspace setback, purchased from Whidens for 6mm ARC only If you are at all serious about checking this . For a limited time only Ill check a case for you for the cost of a case. That is I will not return the case. Send me a case or a box of cases I'd measure the case  or cases & compare it to my PTG go Gauge. & respond with my findings.

Reality is I see no reason for concern though if you are wondering, here are a few options. My Drop in barrel from Pacnor had roughly .004" head space clearance with the PTG Go gauge with no modifications whatsoever. I was impressed, Not sure if this was luck or if this is common! Nonetheless I was pleased!

Id be curious to see what Pacnor did with your custom project. Though Ill repeat that I doubt you have any reason for concern.

Right now I am just curious and didn't know if I needed to do it before I do load development . I have 20 fired cases now  am going next week to shoot more with the new scope and hope to have 100 once fired cases by Dec. 1st then I'll load the 90gr GMX's and see what can be worked up for January Hunting. 
Think I will pass on sending the case,  They seem to be in short supply still .