20x80mm FF Oerlikon

  1. What does “a” after 16 mean? I see Municion.org has the same but with “b”.
  2. The proof mark at 3 o’clock is barely visible. What is it supposed to say?


“a” is the sublot.

The 3h position is the air force acceptance mark, an eagle with the Letter “L” forming its body and inside the inspector’s numer.


I would like to add a little to EOD’s answer. Some months ago there was quite a discussion about German sub-lot letters. I have since found a drawing that shows the terminology and usage of these letters.


Ratenbuchstabe…? Advice letter…??? Please help me and my lack of knowledge of german.


Rate is here a divison = sublot. Not related to any advise.