Montana X-Treme Bore Polish & Cleaning Compound is a mild abrasive designed to aggressively remove fouling, rust and copper. Our Bore Polish is oil-based and holds the abrasive in-suspension, which facilitates the cleaning and polishing process. Recommend for use with stubborn deposits of copper, rusted bores and excessive fouling. Available in injectable syringes Removes Rust, Fouling and CopperPolishes the BoreSyringe Style1 1/2 oz