My views on break in and cleaning. Like others have mentioned, I shoot one and clean until there is significantly less blue. For example, I just began working with a hart barreled 264 win mag. I used boretech eliminator with shrink tubing over the brass portion of my dewey rod to ensure I didn't get any false readings. I use a patch jag combo only. Shot 1, cleaned. It took between 40 to 50 patches before the patches coming out the end of the muzzle were no longer blue. Shot 2, similar number of patches. Shot 3, 30 to 40 patches. Shot 4, light blue after 3 patches and no blue by 6 patches. To me, this paints the picture of tooling marks left by reamer catching copper on shot 1,2 and 3. After shot 4, I believe the tooling marks have been removed. Now, I did study this with a borescope between shots and what I saw matched the results I saw in the patches. After the last cleaning its my MO to shoot a couple of fouler rounds, then take the 5 or 6 now once fired and fire formed brass and run a quick pressure test to determine max pressure. I do this with a magneto strapped on and record the velocity and notes regarding what I am seeing on the brass. Once this is determined, I clean one last time, and as long as it cleans quickly, break in is done. So far on good quality barrels it has played out well each time. Once this is done I do not clean again until accuracy declines or the rifle gets wet/dirty in the field. Every round I shoot is logged and I can go 250+ rounds between shooting on my custom builds ( good quality aftermarket barrels). For reference, some of my factory barrels need to be cleaned in as little as 25 rounds. For another reference, a rem 700 gen 2 5r in a 260 recently went approx 150, then showed signs it needed cleaned. The first few shots that day were spot on, then all of the sudden it was all over the place. We cleaned it, went back out again and right away it was spot on again. Shawn Carlock taught this method and it has worked great for me as well. He has had rental guns fired over 1000 rounds without being cleaned and still shot incredibly well. Edit to add that I am not sure how Shawn feels about breaking in a barrel. When I mentioned that Shawn taught the method I was only referring to not cleaning until necessary.