- My picture from below ["dano1917" will post it for me] shows the nice headstamp markings for a German made 37X263B belted brass shell case with the head diameter of 47mm [1.850-inch]. => Starting at the 12 o'clock position and going clockwise the headstamp markings are: "31" (lot number), "1938" (year of shell case manufacture), "WaA21" (Waffenamt number, acceptance stamp), "6348*" (case identification number with an "asterisk" which probably is related to the shell case head thickness) and "P152" (manufacturer's number code). Both markings "P152" and "WaA21" reveal the manufacturer: "Wurttembergische Metallwarenfabrik Geislingen-Steige" (who later used the code "awt"). => The fired "C/13n.A." percussion primer screw with 3-wrench holes is marke as follows: "147/37." (lot number and year of manufacture - 1937), "Rh.S." (Rheinmetall-Borsig A.-G., Sommerda plant, Sommerda) and "327.C/13n.A." (model number and type of primer in which "n.A." mark represents "neuer Art" or "new model"). ---> The German 37X263B round was fired by the anti-aircraft 3.7 cm FlaK [various models] and by the "Bordkanone", an aircraft gun used for ground attack. Orita 07/10/09