Yes. But if you are going to do this, you also have to account for the weight of that heavy paper, and provide for it to separate from the shot when it leaves the muzzle of your gun. I am still not sure of all the RIGHT Things you have to do, but I have learned some of the Wrong things to do. They are :
1. Do make your "tube" As close to bore size, as would be reasonable. If its too thin, the pressure of being fired with split it in the barrel, providing no real help at all.
2. Don"t make the tube so long that you fold over the top edge on top of the shot. This seems to make a shotgun slug most of the time, and you get no pattern at all !
3. Don't make the tube so thick it doesn't open or leave the shot after it leaves the barrel. I find you have to cut slits in the top edge of the tube, to create " Petals", just like on modern plastic shotcups, to open in the wind and act as an airbrake to separate the paper cup from the shot after it leaves the barrel. I am still experimenting wih how many cuts, how long they have to be, and if by controlling the length of the cut, can you add or subtract from the extra " choke " you give to that pattern.
4. Besides glueing or taping the edge of the tube, you are going to have to find some way to close the bottom and seal it. I am folding my ends over a smaller Diameter cushion wad, un lubed, and then dipping the folded end into melted wax. I stand the whole tube on wax paper to dry, so the bottom is sealed and flat. I am concerned with the distance this combination traveled after leaving the barrel, so I am going to play around with using half a cushion wad in the shotcup, and if that doesn't shorten the travel, then I will switch to some other wad.
5. Do keep the shot in the barrel with a over shot card or wafer, just as you would do if you didn't use a shotcup in your open cylinder gun, or any other shotgun.
6. Be sure to use a proper overpowder card under the shotcup, to seal the gases from your powder charge so they don't burn the shotcup, and start a fire you don't want to have to put out. Using Index Card Stock seems to keep this from happening, because it is coated with something that resists burning.
7. Don't try to push this load out of the gun with a heavy powder charge, expecting it to perform like a modern load of shot. If you read the V.M. Starr article in Bob Spenser's Black Powder Notebook,
[url] http://members.aye.net/~bspen/index.html[/url]
you will learn much wisdom about how a shotgun really works using black powder.
Paul