Japanese 25mm Naval Shell

[orcutteod]

Up for review and comment is a WWII Japanese 25mm Naval shell. To me it's a bit unusual do to the head stamp. It's only the second one I have come across with the concentric tooling circles.

 

[Slick]

Here's a data sheet. The headstamp on yours might reflect its being pre-war(WW2).

 

[Hoeksel]

I have 2 cases and both have concentric circles, so I do not think that is special at all.

One of my cases has no stamp at all; how common/uncommon is that?

 

[ogreve]

Hi guys,

Dow already knows this (as he asked me by e-mail) but for those of you who haven't seen this, you may want to check the following section on my site: http://www.japaneseammunition.com/start.php?main_cat=14&sub_cat=176

Scroll down to the bottom of the page for links with detailed descriptions of the specimens of my collection (particularly the very last link, with the headstamps pictures is of interest).

Yes, Dow's headstamp is strange; the strong concentric circles are somewhat odd, but even stranger is the "half" set of markings: i.e. not completely headstampless, nor provided with a full headstamp. His casing is identical to one that I own, as well as one that I know Kornel owns. Those are the only three I've seen with this very headstamp (though I think that the seller of these casings over here has at least one more). The casing was made at the Toyokawa arsenal, but no manufacturing date seems to be present on it. The 'o' or '0' is wildly odd.

Japanese 25x163 casings seem to have come with headstamps until late 1943, after which they came headstampless. The latest one I have with full headstamp is a Dainippon one, from June 1943 (I have a lot more incoming, so I may soon have later specimens). Possibly this reduced set of markings was used as of mid-1943 to late 1943 (Ken Elks mentions something about a reduced headstamp style in his books - I'll check that later).

Now... maybe unnoticed by all, but the REALLY weird thing shown in Dow's pictures are the markings on the projectile! I've never seen that! I'm trying to figure out what the story is behind those, as I do not recall any mention of that in my reference material.

To be continued...

Cheers,
Olafo

PS: Kornel: headstampless casings are not so uncommon; apparently as of late 1943 all of them came like that.

 

[Falcon]

The lathe tool used to skim off the case head may have been worn or chipped at the time. This would leave stronger tooling marks in the case head.

 

[Hoeksel]

Again, my projectile has markings both between the lower 2 brass bands and on the top brass part of the fuze. Different then the picture shown, but still.

Olaf, are these specific markings strange, or any markings at all?

 

[orcutteod]

Now... maybe unnoticed by all, but the REALLY weird thing shown in Dow's pictures are the markings on the projectile! I've never seen that! I'm trying to figure out what the story is behind those, as I do not recall any mention of that in my reference material.

To be continued...

I mention to Olafo that I thought the markings on the boat tail area of the projectile were arsenal marks similar to what you see on Type99 rifles. But this is probadly not the case here regarding this 25mm.

 

[ogreve]

Hi guys,

I just had a quick check, and my "mental note" about not having seen such markings on these projectiles was wrong: I checked 4 of the loose projectiles I have and at least 3 of them clearly have markings (like those on Kornel's projectile); I had previously possibly not looked down this low on the unpainted specimens, and had only paid close attention to the projectiles on my complete rounds with original paint (which are still crimped in the case, and hence have the case mouth cover this area of the projectile).

So, these markings are not odd at all then.

As for what they mean: they are very tiny and sometimes faint, but the ones in Kornel's picture seem to be the standard IJN acceptance mark (also seen on Kornel's first fuze picture), and the single Kanji ideogram for the Toyokawa arsenal (also seen in Dow's headstamp picture). Kornel's fuze is definitely made at the Toyokawa arsenal, as is indicated by the 'to' Katakana ideogram right before the three lot number letters. Dow's fuze seems to also have been made at Toyokawa, but the character preceding the three lot number letters is somewhat worn; it looks like it was a Katakana 'to' though.

The ones on Dow's projectile are somewhat odd, the 'star-leaf-like' one looks somewhat familiar, but I'm not 100% sure from where. The other one (i.e. the one looking like an 'I' in a circle) appears to be a Katakana ideogram reading 'e'. I'll check my notes on arsenal marks to see if I can find something about that. It doesn't look like the arsenal marks one normally finds on IJN ammo, and AFAIK all 25mm ammo was only manufactured at Kure, Toyokawa or by Dainippon.

If I can find out more about these markings, I'll let you know.

Cheers,
Olafo

 

[Dronic69]

Concentric circles with a date-stamp variation...

Here's perhaps "another" headstamp variation - heavy concentric circles with a date (July, 1943) as the ones shown in this post and on Olafo's website have no date-stamps.

Also interesting is the arsenal stamp (RHS)............its been stamped twice.

Cheers
Drew

 

[ogreve]

Hi Drew,

Nice late headstamp!
Good to see such a late Toyokawa headstamp with full markings. Possibly around mid 1943 the heads started to have concentric circles then...

I have a bunch of 25mm cases incoming; once I have them (hopefully around February (soonest)), I can do some further date checking on actual specimens.

Cheers,
Olafo

PS: The double stamping of the Toyokawa anchor is something one quite often sees on headstamps; I wonder what causes it. I have quite a few casings (all nations) that have some double-stamped markings.

 

[2pounder]

circles

As Falcon states the concentric circles are not that, it is a spiral left in the metal as the lathe tool progresses from the edge of the rim to the centre as the case turns. The reason it is more noticeable could be to do with the condition of the tool, the shape of the tool or the rate at which it progressed across the surface. It is only an indicator of machining under wartime conditions producing accaeptable product not good quality product. 2pr

 

[zwerge]

This looks like the star leaf symbol on the projectile,this is the markings from a North China type 19 rifle.It is a cherry blossom,here it is on the Sasebo arsenal marking.