I'm not a big fan of bore brushes, of any type. While the brush itself won't harm your bore, the carbon that get's impregnated into it will. It'll turn that brush into a lapping tool. There are too many good bore cleaning chemicals available now that eliminates the need for a lot of brushing. I don't think there's enough emphasis put into keeping the chamber & throat areas clean. From what I understand, heat will kill your barrel quicker than a dirty bore.