Take care of your investment. Tiptons Best Bore Brush meets military specifications and its components wont scratch or harm your bore. Single-piece, brass-wire core threads through the brass coupler to prevent separation within the barrel. Bristles are made of high-quality bronze, which is softer than barrel steel yet strong enough to aggressively scour lead and copper fouling as well as powder residue. Bristle count is 20% greater than most Recommended for quality one-piece rods with an appropriate bore guide. Per 3. Available: .22 cal. .243 cal./6mm .25 cal./6.5mm .270 cal./7mm .30 cal. .338 cal./8mm Cancer and Reproductive Harm- www.P65Warnings.ca.gov. Type: Jags & Brushes.