I based that on using the same ammo factory used according to the included marked and signed 3-shot target which showed the rifle barely got passed. (Vanguard's 1.5" accuracy guarntee) Granted, it wasn't ammo from the same lot #, but did match brand, bulletand grainage. So perhaps I should have included those initial 3 factory fired rounds.
I just don't see where it would hurt to do the process, other than ammo cost, which you still have to buy eventually anyway. Whether button rifled or hammer forged or whatever, all will have various degrees of marks in them and it helps remove them.