There is very little information available about the 10mm Gaupillat except a note from Erlmeier, Brandt stating that it was discovered at the 1975 Lucerne Arms show in a box labelled: Nombre 25 – Calibre 10m/m – Cartouches pour Revolvers a percussion centrale. It would seem to fit in the same category of other French rimmed revolver cartridges by Galand, Perrin and Devisme. (Erlmeier, Brandt Ref. 145A).