As stated - no harm but you will have "foul" . . . ooops . . i meant fouling. Just a note though on the use of something to coverr the powder. Cornmeal "plugs" will turn to dust - if you use a felt wad, just remember that at close range, that wad is a "projectile". When I was active in reenacting years ago, they were banned and I believe they still are. The same way as ramrods were to remain in camp and not be on the field - if some "ninny" were to leave it in his barrel and shoot - that too would be a "projectile". It's just common sense. Have fun and enjoy!