20x71RR Japanese Type 99 "8 12 - 01" for the Navy Oerlikon FF aircraft cannon

Another good discount bin find at SLICS. I know “8” in the headstamp is not “8” but a Japanese symbol but I am hard pressed for time and will find the correct symbol later. May anyone translate the headstamp for me? The cartridge has 3 mouth crimps.


Strange that nobody answered your query. The main title is incorrect.
It is a 20x71RR Japanese Type 99 (not 91) for the Navy Oerlikon FF aircraft cannon.

Maker is Dainippon Heiki Kabushiki Kaisha (or Dainippon Arms Co).
01 = 2601 (1941). 1 = Type1 Oe short case. 12 = 4 month period September -December.


Thank you for correction. I found it at SLICS and posted it immediately, so had no time to research too much.