Like stated above, there are a dozens of different ways to skin a cat. I've either done the 5 shot, clean, 5 shot clean for 20 rounds... or ive done zero break in at all and I havnt noticed a difference in coppering, or fouling, ect.... However I must admit that after spending the money on GAP rebarreled action... I followed their "break in" to the T. But for factory rifle barrels... its not worth the cost of ammo imo.