Tipton Best Bore Brush 243/6mm Caliber, 3-pk. Tipton's Best Bore Brushes are the finest brushes ever offered. They meet or exceed military specifications and are designed to satisfy the shooter who wants the best tools to maintain their guns. The components of Tipton Best Bore Brushes will not scratch or in any way harm the finest bore. The core is a single piece of brass wire that passes through the threaded brass coupler, guaranteeing that the core will never separate from the coupler in the barrel. The bristles are made from high-quality bronze, which is much softer than barrel steel but more than aggressive enough to scour away lead fouling, copper fouling, and powder residue. Each brush contains the maximum number of bristles that can be inserted for the caliber, 20% more than standard brushes! You will feel and see the difference. Because of their density Tipton recommends that the Best Bore Brushes only be used with a quality one-piece rod and an appropriate bore guide.