Tabbit: Is the patching lubricated? It doesn't look like it. Is there any reason why a pre-lubed patch covered by a thin ( hankerchief thin cotton) patch to separate the lube from the powder) patch could not be used in this set up? Or an OP WAD over the powder so that you can run that down the barrel after dumping down the powder, to separate the pe-lubed patch from the powder during transit, and, of course, seal the powder gases behind the PRB? In a 20 gauge Fowler, the OP wad would be small enough to easily fit down the 12 ga. hull, no?
Nice pictures, and great inspiration. Thanks.