I make paper cartridges for a Bess and a Potzdam, the paper acts as a sabot and the accuracy is quite surprising. I also make the Pat 1858 enfield paper cartridge which I use a 530 grain pritchett bullet, these you can shoot all day and not have your rifle foul.
I am not surprised that this tapered cartridge works in a rifle, of larger bore as I guess by the looks the paper acts once again as a sabot. Save mucking about with flask and loose ball etc. Will post my results in due course.
Great article Bruce, well executed. Thanks.

Cheers

Gordon