Wilson Combat's Ultima-Lube II bore polish will improve the condition of bores while removing copper fouling. Bore Polish contains no ammonia or synthetics and will not harm metals. Ultima-Lube II bore polish may also be used as a first step to remove lead or hard carbon buildup. This bore polish removes copper from the lands and grooves while leaving the embedded copper - in the micro-fractures of the bore - alone. The result is a smooth, polished bore which improves overall accuracy.