During the cleaning process there is one area that I sometimes neglect, the face of the breech plug. When using the cleaning jag and patch to clean the barrel, you can wipe until the barrel appears to be clean, but the face of the breech plug can still have a buildup of burned black powder, or fouling. There is a special tool created just to solve this problem, the fouling scraper.
Just install the fouling scraper onto the ram rod and slide it into the barrel. Once the scraper rest against the breech plug, turn in a circular motion. Pull the ram rod out carefully and you should see fouling on both sides of the scraper blade. You may have to repeat this a few times, depending on how much fouling has built up. If there is a buildup of fouling, the scraper will make a softer thud when it hits the breech plug. After scraping you should notice the scraper sounds more like metal on metal when it taps the breech plug. This should be a good indication that the fowling has been removed.
If the fowling is not cleaned regularly it can build up to the point that is begins to block the hole from the drum into the barrel. This can then cause misfires because the cap firing only hits the fowling and not the fresh powder.
So to ensure your muzzleloader has a better chance of firing off the line, be sure to clean the face of the breech plug after every outing.
4-24-2020 Update: After posting this article I had a comment recommending this breech cleaning brush made by Bill Slusser, a barrel maker. See the images below.
It was also noted that the square breech cleaning tool will not work on some breeches. A round cleaning tool is needed for these breeches. I really like the idea of the brush though because it should work with either breech type.
For additional information on cleaning a muzzleloader, please read this article: http://traditionalmuzzleloader.com/index.php/cleaning-a-muzzle-loader
