Pro-Shot 20mm Shotgun Chamber Bronze Brush 12 Gauge 5/16-27 Threads. These Cleaning Rods & Accessories from the groundbreakers at Pro-Shot feature heavy-duty stiff bronze bristles for a powerful clean no matter the weapon or cleaning system. With a looped end the Pro-Shot 12 Gauge Bronze Cam Brush easily fits into the chamber for repeated cleanings without damaging the finish. It's the ideal way to keep your firearm properly maintained. Pick up your Pro-Shot Bronze Cam Brush today for a superior piece of gun cleaning equipment. Specifications for Pro-Shot 20mm Shotgun Chamber Bronze Brush 12 Gauge 5/16-27 Threads: Manufacturer: Pro-Shot Caliber: 12 Gauge Package Contents: Pro-Shot 20mm Shotgun Chamber Bronze Brush 12 Gauge 5/16-27 Threads The Pro-Shot 20mm Shotgun Chamber Bronze Brush 12 Gauge 5/16-27 Threads 12SB is a quality addition to the Pro-Shot lineup. For more great deals on Chamber Brushes by Pro-Shot please browse our Pro-Shot Gun Cleaning Kits page. Pro-Shot 20mm Shotgun Chamber Bronze Brush 12 Gauge 5/16-27 Threads