see this here
https://www.youtube.com/watch?v=IzMhz_hZlsI
and looking for more https://www.youtube.com/watch?v=cKQIViucy5M

looks like an interesting book, you maybe never make skin cartridges at all but its an forgotten knowledge thats good to have in the library

amazon deliever it worldwide
https://www.amazon.de/MAKING-SKIN-CARTRI...2C64&sr=1-1

and btw, never see a .50 caliber percussion revolver before https://www.youtube.com/watch?v=9yzevgYcCr8