As of late I've been plinking with .32 S&W Longs in a S&W 331 .32 Magnum Airlite. They're accurate and recoil, even in an 11 oz. snubby is virtually non-existent. However, I'm having trouble removing lead buildup in the chambers. The manufacturer warns against using abrasive materials, which I assume include a bronze/brass brush, so I'm relegated to a nylon brush and Hoppe's. These won't cut it. Appreciate your suggestions.