Wilson Combat Bore Brush 9mm/.40 Nylon. This high quality nylon fiber brush is the preferred tool of choice for those who know the value of a thorough clean. The "Double Star" shape of the bore brush provides two distinct cleaning edges preventing the shedding of bristles and repelling stray fibers that leave debris in the brush. For those who want a double star pattern the nylon star pattern can be removed with a simple half turn of the brush handle. A fine nylon star could be used as a last attempt to clear your bore but a stiff double-star will do the trick. Also works great to knock out sand and powder from choke tubes.;. Specifications for Wilson Combat Bore Brush: Manufacturer: Wilson Combat Fabric/Material: Nylon Caliber: .40 S&W Package Contents: Wilson Combat Bore Brush Wilson Combat 732-9: Bore Brush 9mm/.40 Nylon