Case Stretch

[Kurt]

Steve,

To get a good head space measurement. Use a good solid rod that will fit inside the case all the way to the bottom.
Chamber that empty case close the breach and push the case to the reach block with the rod. This would be best if the rod was just an inch above the muzzle and take a depth gauge and measure the distance. Now open the breach with the rifle in a cleaning rack and push the case and rod all the way in. take a measurement and zero the depth gauge. Close the breach and push on the rod till the case rests on the block face and take the measurement again.
I did this when I formed the basic .44 brass that had rim thickness way over what would fit the rim recess and turned it down for a proper fit.