Brownells 20 Gauge 5/16-27 Male Bore Mop, Pack of 3

This wool mop is built for shooters who want effective, safe bore maintenance. Virgin wool holds more fluid for full coverage and the brass parts are smooth and non-damaging to your bore. Material composition includes wool fibers, brass shank and precision-engineered coupling components for enhanced durability and performance 2.87 inches length, 5/16-27 thread