put it on the end of your range rod( you do have one?) and run it carefully down the barrel to the breechplug face. Turn the scraper so that you are tightening the scraper on the rod( usually clockwise) to remove the crud that gathers on the face of the plug. Pull the rod and scraper out, flush the barrel with water and soap, dry, and put a light down the barrel to check to see that the breech face is clean. Usually you will see crud on the face of the cleaning jag with a cleaning patch on it if there is some crud, still.