The brass ramrod from the kit is intended for cleaning the bore, sometimes for knocking out a stuck bullet.
A brass brush is used to initially clean the barrel from lead deposits. It is difficult to scratch the barrel with such a ruff, due to the fact that the metal of the ruff is much softer than the metal of the barrel itself. After pre-cleaning, you can use a synthetic brush from the kit: with it, the main cleaning of the barrel after shooting is carried out.