Well, G.L. Rasch's son may just have made this one from sourced components. If there aren't any issues and some checks are made, sure it is possible to shoot it. It was more than likely tested in some manner by black powder and use of black is a possibility. Then there's the smokeless cartridges from Gamebore, which also peddles black, and Polywad. Low pressure from 65mm cartridges would be the goal.

Kind Regards,

Raimey
rse