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20mm mk3 oerlikon??


Well-Known Member
Premium Member
a friend of mine has these 2 shells, I think are 20mm mk3 oerlikon, but maybe someone cauld help me to identify??
thanks in advance my friend
best regards.

here the shell, the right one had a few of original paint
only the left one has visible markings.
marking on fuze; MK 25 - 1 RR
marking on body:
MK 3 24 LM LOT 727
sorry for picture but markinags are very light.....
anything drawing, plate or icture it's appreciates.
many thanks
Hi Fert,
These two are both oerlikon projectiles as you thought, i do not have any reference for the MK3 rounds that i can find although i will keep looking. They are both HE or poss HEI i would have thought.
Ok i have got out two from my collection, both of these are MK3 1940's dated US rounds the brass one is naval. These both have brass MK26 fuze's. Not sure what the RR stands for i to have that marking on one of mine.
many thanks for info guys,
last problem was the color, the right one is black painted, and I did not find this in plate posted here courtesy by investement.....


in these plate a british AP oerlikon has a conical log tip and black painted body?? (1st from left).
I can't see a black painted HE shell, maybe mine posted are drill or similar???
thanks again my friends
best regards
Hello, This weekend I purchased a 20mm oerlikon at a flea market with exactly the same markings "MK3 24 LM LOT 727", also painted black..
but what I can't determine from this thread, is its nationality, is it now british or american?

Kind regards,
Typically U.S. Navy ammunition uses Mk and Mod numbers whereas Army ammo uses M numbers (Model). There are a few exceptions like Mk numbers on some Army 3 inch antiaircraft cases.

I'm unfamiliar with the UK designations for ammo components for Oerlikon.
Sorry to be a misery but if those are HE/HEI shell then where is the rear sealing disc ?

Or have I got it wrong and the later Oerlikons do not have any fitted ?
I only ever had two HE or HEI 20 mm Oerlikons and both had the base disc fitted and both were dated 1942 and 1955 ish from memory.