Browning Bore Polish - Step 2 # 124024 Removes copper, polishes the bore and improves accuracy. Polish up on your accuracy. This second stage cleaning product has a proprietary formula that improves bore condition while safely removing accuracy-harming copper build-up. In addition to removing copper fouling, it also removed lead and powder residue -- the enemies of accuracy. Evaporates quickly Contains no ammonia, pH neutral Pinpoint applicator 4 oz. bottle.