Otis 10mm/40 Cal Bronze Bore Brush

Sized for the 40 caliber bore, which covers 40 S&W and 10mm since they share a bullet diameter. Phosphor bronze bristles cut carbon and copper without touching the steel around them, and the brass stem keeps the brush from becoming the hardest thing in the barrel.

Otis stamps the size on the stem so the right brush is easy to pick out of a drawer full of them. The 8-32 thread is the common size on Otis cleaning cables and conventional rods alike. One or two wet passes followed by patches will pull a session of fouling out of a pistol barrel.