Well now see therein lies the confusion that I hope someone smarter than me chimes in on. I've heard it described both ways. I've heard H (I think) describe copper gone and Todd Hartnett describe leave copper remove carbon. Either way I took from it as don't clean the crap out of the bore Lol.
There is a group of bench shooters who advocate breaking in a barrel by taking a shot, cleaning the barrel, taking a shot. And some of us disagree with that completely. I've talked to people and read of others who say the barrel makers and those who sell cleaning products advocate heavy cleaning in order to wear down barrels and sell more cleaning products. I tend to believe this, I see no reason for over-cleaning, except to wear out a barrel or sell more product. Unless the barrel is so dirty that it's a safety issue or accuracy issue, I personally think most people probably clean too much. Barrels definitely need to be cleaned when new, but scrubbing a barrel with a brush in both directions in my opinion is a bad idea.
Todd Hartnett said he mildly cleans after shooting (a patch or two total down the bore) and when asked when does he clean the bore thoroughly. He said when accuracy degrades And then run some fouling shots until the accuracy returns. He also stated that clean bore is more the issue than a cold bore.
Sweets 7.62 instructions say to work a saturated patch back and forth in the barrel for 1 minute but do not leave it in the barrel for more than 15. Then it says to patch out the 7.62 with dry patches until clean. Then follow with oil to recondition. It does not say to use a brush back and forth.
Now, normally I use a bore snake with a little clp to clean the barrels of all my other guns and I have never had a problem.
That said, this breaking in the barrel is new to me as I have never done it.
Following was my method:
(Sequence of 10 times)-1 round shots, patch out with one hoppes patch, copper brush breech to muzzle 1 time after diping in hoppes, dry patch out until patches are clean, 1 patch of clp followed by 1 dry patch.
2 round shots using the above method between eash set for a total of 10 rounds.
5 round shots using the above method between each set for a total of 10 rounds.
Come home and use multiple patches soaked with 7.62 for 1 pass each until no bore residue.
Dry patch out for several patches to make sure 7.62 is all gone.
Run an oil patch through 2 times to recondition the bore.
Before I go shoot again I will dry patch out any oil residue and shoot and clean normally. (2 swipes of the bore snake with a little clp on the tail end)