You guys should check this out:
Punkworks Tests
Near the bottom of the post it refers to Paint to Barrel Match Testing (P2BM). Make sure to watch the videos and check out the data sheets.
Also look at the Barrel Break Testing information as well. It relates back to the P2BM Test in regards to underboring causing more barrel breaks.
Bryce and Gordon did a really good job with their testing.
There was also a discussion about it on here as well:
Paint to Barrel Match Testing