the more often you remove a lil copper from handlapped barrels, it becomes seasoned, ok, I clean after every shot for 5 shots, after each shot I remove the fouling from the microscopic tooling marks left after lapping, one shot those tooling marks are full, the more you clean it and oil it the more seasoned it becomes, so it doesn't pick up as much fouling, and it lets go of it easier for lack of a better word.
I cleaned my 7mm AM Lilja barrel, every shot for 10 shots, then every 3 shots for 10 groups, with 480 rounds downrange I have never picked up a hint of blue on the patch if I use a nylon brush.
breaking in aproduction barrel is a waste of time IMO
RR