Problem with this 37×155mm N-37 autocannon shell


Does anybody know which country made this 37×155mm shell? ‘O’ or ‘0’ is at six o’clock of its headstamp, ‘K’ asides with some strange codes like ‘b’ and ‘8’ are at three o’clock. The says this kind of ammo was manufactured by the Czech Republic, Poland and Russia, is this one of their products? I’ve only seen the U.S.S.R-made 37×155mm shells which all have ‘184’ code on their headstamps.
Thanks in advance for your help!



Rick, a very interesting case you got there!
What is the background of this one? It could help maybe.


This case was bought from an online grocery. The seller confused it with the Chinese-made 37mm Type-31 (direct copy of the Soviet N-37) round which would actually have ‘民’ (inspection mark used before 1965) on the headstamp.97B447D36D3C078D3351063769AA86DE
Oops! I don’t know the exact meaning of ‘戌’ and the numbers, factory or year code I guess.
Besides, the seller also has some cases of this type, one of them appears to be headstampless! I can only identify these soviet-made N-37 cases that have ‘184’ code on them. So it’s really hard to say where made this shell.




The ‘K’ would indicate made of silicon brass(tends to have a lighter/paler colour than normal cartridge brass), a favourite with Eastern Bloc nations.


Rick the Chinese case seems to be made in 2011. That is quite late for this caliber.


You are not kidding! The three combat aircraft to be armed with the N-37 were the MiG-15, MiG-17 and Yak-25, all of them introduced in the 1950s. China finally retired the Shenyang J-5 (MiG-17) in 1992. There may be a few still around in North Korea and Tanzania.


‘民’ is the inspection mark indicating the shell is qualified, China cancelled this mark since 1965, so the case was definitely maded before 1965.
In China, there is a cycle of twelve years, each with a different animal. Their characters ‘子, 丑, 寅, 卯, 辰, 巳, 午, 未, 申, 酉, 戌, 亥’ corresponds to ‘rat, ox, tiger, hare, dragon, snake, horse, sheep, monkey, cock, dog and boar, so ‘戌’ indicates the case was made in the year of the dog. Considering China received MiG-15bis models in 1950, we can finally figure out the case was made in 1958.
Number ‘11’ and ‘12’ might be the code of production batch and inspection unit respectively.


If so the case was made in 1959 but why the switch of positions for lot and year at the 9h position?

Here a 37x25R from the same factoy out of 1957 where the year is on the correct lower 9h position.

Image from the web: