those quality control markings were also used by other factories.
The "Sp" mark was also used by:
- Polte in Magdeburg,
- Rheinische Munitionsfabrik (Rh. M.F.) in Düsseldorf,
- Algemeine Elektricität Gesellschaft (A.E.G.) in Berlin,
- Artillerie Werkstatt Spandau (AWS) in Berlin-Spandau,
- Gelsenkirchener Gusstahl Werke (GG or GGW) in Gelsenkirchen,
- Geschoss Fabrik Spandau (GFSP) in Berlin-Spandau
The mark "Sp255" was only used by Patronenfabrik Karlsruhe, the marks "Sp252", "Sp289" and "Sp406" were used by Polte Magdeburg.
As said before the "Sp" mark was used from the end of 1915.
The Patronenfabrik Karlsruhe used from 1897 to 1898: AWS 10; 1898 to 1902: Dr 1; 1899 to 1915: crown and Ke; 1907 to 1915: crown and Ke with number; 1915: HL 21 and 1916 to 1918: Sp255.
the meaning of the "flaming bomb" was unknown to me. Could you tell were you found this information,please?
I'd had an idea the 'Sp' stood for 'Sprenggranate', or HE shell? I have a POLTE, MAGDEBURG JAN 1916 10,5 cm. case with 'Sp252'.