I was goofing around with a few ways to indicate the bore in and based on chads spud rod doo-dad I thought I might try a couple out of the box idears. You can see by my marvelous photos why I don't post pics.
This is an attachment I made to fit in a starrett wiggler holder. It is just some drill rod with chrome balls soldered on. The plumb keeps it riding on the bottom of the bore. The barrel is in the 3jaw just for display reasons, and would be indicated in your favorite manner. I also hit the jackpot and scored a .00005" indicator for a whopping $80 locally.
This is an attachment I made to fit in a starrett wiggler holder. It is just some drill rod with chrome balls soldered on. The plumb keeps it riding on the bottom of the bore. The barrel is in the 3jaw just for display reasons, and would be indicated in your favorite manner. I also hit the jackpot and scored a .00005" indicator for a whopping $80 locally.