Having owned two of these paper cartridge Sharps in the past....
I must say that one would run a string of volleys and go like the energizer bunny. The other would start to bind up from fouling almost immediately. It was a frustrating gun because of the fouling, yet a wonderful gun given it's accuracy.
The falling block design is a bear if you get the mechanism seizing up between shots.
Slash actually taught me how to roll my own using nitrated papers. And I have to admit it is easier then reloading with brass cartridges. Plus you can load one of these Sharps in 3 different ways. The guns are very versitile....and for every negative, have 5 positives.