the thing you to know is . . . . .
The length the gauge needs to be from the base to the datum line.
It's some where on the shoulder taper as measured from the base.
The gauge really can be just a peace of miled steel cut to the right length and a minim diameter. Or you can fire a round and measure the fired case and you can see the actual chamber condition.
As a gunsmith I do this all the time. (Do not try this at home) (unless you live in the woods.)
Last edited by norsecat; September 13, 2012 at 11:27 PM.