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37mm rounds for U Boats?


Well-Known Member
Hello all,
I've just received another German 37mm round with the 'M' (Navy) impression on the headstamp. I noticed the similarity with a projectile I already have which I thought was a tracer and probably used with a revolving cannon.
The existing projectile had an alloy base plug which I did not want to risk removing as it was so fragile. The recent round has no base plug but clear signs of alloy residue inside. I'm told that these were commonly used on U Boats during WW1. Both cases were made at Karlsruhe, one Mk III dated 1904, and the other Mk IX dated 1908. The 1908 one has five punch marks on the headstamp, could these be re-loading marks? I'd appreciate any information on these and whether they were used on U Boats. I can't imagine a U Boat being armed with a revolving cannon?
Thanks in advance,


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These were fired by

The German made 1Pr. Maxim guns, and revolving cannon reissued for Balloon defense, also the sockelflak cannon. I don't know if U boats carried Maxims, I rater doubt it. The cases were reloaded for ever as long as they were usable.
Hello Gspragge,
Thanks for your comments. I have a 1918 37mm round which has the characteristic curved mark on the case indicating that it was fired from a revolving cannon. It hasn't got the Navy 'M' stamp. My confusion now is that I have three 37mm cases, (two navy one's), and five projectiles. Two projectiles are fuzed, two more are base filled with no nose fuse, and one with what looks like a transport plug to leave a space for a nose fuse to be inserted prior to use. I think that the cases don't neccessarily go with the projectiles which were with them when purchased so have ended up with a bit of a puzzle. Any ideas welcome?
The 1918 case

is a wartime Army case, so there is no Navel mark. The plugged projectile could be a practice ? Have a look at my album here, you should match yours up with mine. Any of your cases go with any of your projectiles. A practice projectile has three strikes cut into the body that look like the British Broad arrow mark. Or it is a regular PD with a plug instead of a fuze. You might find the Marine mark on prewar made PD projectiles, those you should match with Marine marked cases.
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37mm German

The german navy is also on the grond (coast defense)
and infantery used his munitions.
See this translated shells from 1914 to 1918
Hello Andre,
Thanks for your help. Am I correct in assuming that from L-R projectiles 1 and 6 are the same except that 1 has the base missing, also can you tell me how this type of fuze worked, was it a tracer?
Best regards,


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Ah , part of your problem is,

that two of your projectiles are British 1 Pdrs. What markings are on them?
there should be something stamped into the bodies between the bands or below the lower band. Sometimes on the base as well. The German projectile uses the Desmaresk PD fuze, same almost as the French do and there should be the Imperial Navy Crown over M on the body. The three German projectiles will go in any German case. The case for the PD will not have crimp indents (though if reused case you can see where they used to be before resizing)


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base fuse incendiary German 37

Hello Guy
This is the system ignitor for impart the lighting to the incendiary charge.
In reality it is not a base fuse;

37mm again?

Hello Gspragge,
The projectile on the left has no visible marks on the side but is stamped VSM with an S and a right pointing vee on the base. (Vickers Sons + Maxim)? The fuze looks like a ZZ 1505. Small K on fuze side.
The projectile on the right has (VSM faint under paint between the lower and upper rings) and a single Vee on the base. The fuze again looks like a ZZ1505 or ZZ1505A, (with lock pin)? Small H on side of fuze.
I have now three cases, two are marked Crown over M, both Karlsruche, and one case with the revolving cannon scrape dated Juni 1918, (French)?
I'm begining to get confused now so won't bother with the other two projectiles for now! It would be nice if the two M marked cases fitted with the two similar projectiles but I know very little about 37mm ammunition.
Sorry to land you with all this confusion, but would appreciate any help?


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You have ;

Two Vikers Sons & Maxim marked 1 Pr. with the Nordenfelt PD fuse. The one with the S mark has a cast steel body, the other cast iron. They are both nice. You need two British 37x95 cases, either unmarked or VSM marked.


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Many thanks,
I will have a close look at them tomorrow and work out what I should be looking for.
Hello Gspragge,
I've sent you a PM, can you let me know if you received it, not sure if my computer is behaving.