Pro Shot Nylone Bore Brush for Gun Cleaning - 45 CaliberNylon brushes scrub rifle bores without damaging the rifle bore surface... That's because nylon is softer than steel and other metals.. But That's Not All! Pro Shot Nylon Bore Brushes have a unique bronze core... So that even if the core of the brush touches your rifle barrel bore or muzzle crown, it won't do any damage. Order Extras... Brushes DO Wear Out - You want the brush to wear out, not the rifle barrel bore. Order the Pro Shot Nylon Bore Brush that fits your caliber. It will fit the bore snug when its new. As you use it, it will gradually wear out and get to have a looser fit. Eventually it'll be time to replace it. Use your wore out brushes for smaller calibers or for patched bore cleaning with Bore Paste. We have brushes, jags, patches, cleaning rods, and rod accessories on our Gun Cleaning Hardware Web Page. All other gun cleaning and service related products are on our Shooting Accessories Page.