OK...I'll be the odd man out here. I've been a hunter for 40 years. I'm also a reloader. I own, shoot, and have developed loads for each of the six rifles that I own and they all shoot groups under an inch at 100 yards with one capable of 1/2" - if I can do my part.
My "break-in" process is to thoroughly clean a new rifle when I bring it home and, then, take it to the range with various loads. I never let the barrel get hot (I sometimes wait 5 - 6 minutes between shots) and I don't do any cleaning between shots. When I find the tightest group, I take the rifle home, clean it, and then do some fine-tuning on the load it liked and, a few days later, take those loads, shoot them and find the one that is most accurate.
So, all I can say is that it has worked for me. It still works for me. And will probably work for me in the future.
Some example results attached: (Note: The first picture is of factory loaded Core-Lokts. The next two are from one of my .270's. I own three .270's and three 30-06's. Two Howa Model 1500's- .270 and 30-06, one Winchester Model 70 in .270, one Browning A-Bolt in 30-06, One Ruger M77 MkII in 30-06, and one Marlin XL-7 in .270). I mention the different brands to show that this method has worked in more than one brand.
NOTE: The three rounds on the outside of the target in the third picture were brought to you by the .300 Win Mag w/muzzle brake being fired at the next table. Good grief!
