This was one of the experimental cartridges by Eduard Rubin in the mid 1880’s. The bullet was loaded into the case with a distance ring that stopped at the edge of the chamber when the round was fired. The idea was to have a compressed black powder charge into the case, with a smaller diameter bullet, but the invention of smokeless propellant in 1886 rendered this whole idea obsolete. It was an interesting primer design with a single flash hole on the Berdan type primer, for which Georg Roth obtained a patent in 1887. See also Motz & Kohlmann Vol. 3 p.118and 288. (Roth Case No. 228).
