Thread: Barrel break-in

My understanding of break-in is that it is all about copper fouling interfering with the surface oxidation of the throat / barrel.
I would guess that over the years there have been 10 new barrels shot for the first time by people at my range.
Of those 10, I guess half have hardly made a green mark on the first patch then nothing and half stained at least five patches and one was green for ten shots and needed fifteen to run clean ( A tikka)