We like to refer to our Brass Core Bore Brush as the Benchrest Quality No Harm Bore Brush. The Brass Core/Bronze Bristle Brush cleans the barrel completely and is totally SAFE for use on all firearm bores. A Brass Core brush holds the bristles longer and can withstand frequent harsh use. Filled with superior over-sized bronze bristles that are larger than standard. They fit tighter and last longer. More bristles per inch on a Pro-Shot bore brush watch us out clean the competition. Looped Brush End. The ends of our pistol, rifle, and shotgun brushes are looped, not sheared off like lower quality brushes. A looped end makes the brush superior and safer to use instead of a cut open end. Brass Coupling. Our brass coupling is made with precision threads to stay screwed into cleaning rods and will hold the brass core for long lasting tough use.