Hello,
In jager's book on german artillery some obsolete guns in service with army are mentioned in the tables and some illustrations but very little else is given about them.Guns like
9cm C/73/91
10cm Kanone 04 of krupp of 1902-03
13cm Kanone 09
Schwere 12cm kanone 1880
15cm ringkanone of 1892
15cm sFH model 1893
Apparently they all lacked the modern recoil system so were regulated to fortresses.Does anybody have information of any action reports involving these guns or their pictures ?