@John Spartan, perhaps I should have been a little clearer in my response. How one loads a smoothbore is really a personal preference. That preference is based on how that smoothbore is to be used.
You are expressing an interest in the Napoleonic time period. In this case the preference can be based on the use of your 1777 Charleville AN IX in the military context. That would be use of a paper cartridge and a the use of an undersized ball for ease of loading in a combat situation. There the advantages are ease of loading, and experiencing the shot to performance of a soldier in performance of a line of battle situation. The disadvantages are that the use of the undersized ball, while accurate enough for minute of opposing line of infantry is adequate, is not adequate for any kind of accuracy on target or for hunting. A paper wrapped cartridge load can be developed with a slip to fit ball and paper wrap for hunting or target use as evidenced by
@Brokennock's example above, but that paper wrapped cartridge is not representative of the paper wrapped cartridge used during the Napoleonic Wars.
The other methods have the advantages of an application for use with both ball and shot. As Brokennoock's earlier post has stated there are at least two or three other methods of loading. Each has advantages. One advantage is the the load from shot to shot will be consistent and have a slightly tighter pattern than the mor historic loading methods. The primary disadvantage is that the other methods take a longer time to load and reload. You have to be more concerned with the build up of fouling in the bore and developing a consistent hold and sighting picture. The use of your Charleville will require a different hold when using a patched round ball, round ball nestled in a wad of tow or near bore sized bare ball held in place by some sort of over ball wad or card.
When used with shot, an over powder wad is used to provide a gas seal between the igniting powder charge and the column of shot. Sometimes a lubricated wad is placed to cushion the shot, then the shot and an over shot card or well lubricated fiber wad to keep the fouling soft and lubricate the shot column as it leaves the barrel (Skychief Load). You will need to develop a more shotgun like hold and sight picture when your Charleville is loaded with shot and a different sight picture if doing wing shooting, squirrel hunting or turkey.
Let's see. I have talked about three methods for loading with round ball and two methods for loading with shot. I have left out a primative shot load using field expedients of dry grasses as the over powder/cushion wad, shot and available wadding for over shot. The advantage is that this is a historic practice for you to experience. The disadvantage is that the historic patters will be more open and effective range is shorter.
So your load will become a personal preference based on how you will use your 1777 Charleville AN IX. Welcome to the world of traditional muzzleloading.