Nagant espagnol
Spanish Nagant 1878-1886 marked “G y U” crowned.
I believe that one can specify that it is about a manufacture of GABILONDO y URRESTI, manufacturers of weapons (guns and revolvers) with Eibar, under the marks Eibar, Ruby, Danton, Bufalo, Llama, Mugica, Perfecta, Plus Ultra, Radium, Taulers…
Michel of the South