This is a box for 25 cartridges in 11mm caliber, for the regulation M.1884 model revolver. The gun was an Orbea Hermanos copy of the Smith & Wesson No. 3 “Russian” model.
Cartridges in this box (M.1915) haver solid heads, brass cases, copper (or gilding metal) primers and lead bullets. Fil. 41 flake powder. No headstamp. Older cartridges with folded head are known.
P.M. Sevilla stands for Pirotecnia Militar de Sevilla.