The T-17 scrubbing bore cleaner effectively cleans and neutralizes the harmful fouling in the bore from black powder and black powder substitutes. T-17 also helps to remove plastic, copper and lead deposits that could effect the accuracy of your rifle. A micro thin layer of protectant is left in the bore to prevent rust and corrosion. The foam penetrates even the most caked on fouling and eliminates the need to brush your barrel. Simply spray into your barrel and let stand for one hour. The foaming agent does all of the work for you. Wipe your barrel clean and treat your barrel with T-17 Seasoning patches to prevent rust.