Hi Crow Feather,Are you talking about the brass cartridge case type or the cardboard paper type? I have looked everywhere on the net for that size cardboard tube without success.
The tubes are made and sold my Hahn Machine Works for use mostly in guns that have his conversion.I have used Pedersoli brass cases and they work well but are a pita to clean and the best bullet is a proprietary Pedersoli one with a heel that fits the case. Also they are outrageously expensive if even available.
Bunk