The Thompson/Center Muzzleloader Cotton Bore Swab is designed to oil rifle bores or to apply Natural Lube 1000 Plus Bore Butter as a seasoning agent. The 100% cotton swab is furry soft, yet durable with 10-32 threading that will fit most ramrods on the market. The Thompson/Center Cotton Bore Swab is the tool of choice for cleaning and seasoning your .50 caliber Muzzleloader barrel.