Pro-Shotâs Copper Solvent IV is a Superior New Generation Formula that is made specifically for copper and powder fouling, while providing rust protection for your barrel. The New Generation Formula has been developed and tested extensively to assure itâs even superior over our last famous copper solvent. How it works fast & effectively to clean your barrel: The symthetic formula uses positively charged ions activated additives that have a special affinity for copper and its oxides. The positively charged ions search out the negatively charged copper and copper oxide molecules. They bond and release the copper from the surface of the bore to provide a superior clean surface without copper and powder fouling! Copper Solvent IV is a highly effective way to clean a barrel without the harsh and toxic chemicals used in traditional bore cleaners. The new innovative formula is a smarter, healthier, and environmentally safer way to clean than the old brute force method of throwing harsh chemicals at copper fouling. No offensive odor. Improved Accuracy! A non-fouled barrel can give you improved accuracy. The New Generation Formula can give you a totally fouling free barrel!