All correct.
This line of ammo has somehow captured my heart, and I take a particular interest in it and I'm trying to figure out who made the various specimens, etc.
There's much I can (and cannot) tell about them, but I shall try to summarise it. A significant part of these items can be seen in detail at my site, on the subpage:
http://www.japaneseammunition.com/start.php?main_cat=14&sub_cat=187&access=view&exp_sub_cat=187
(make sure to follow the red links at the bottom too, as these show many detailed descriptions of specimens of mine)
Please note however that I have to update that page; many new things are now known to me, and several new highly interesting specimens are not shown yet!
Here's some info:
As Ozzi wrote, there were several different types of projectiles in use. Confirmed are at least the following ones (by my distinction):
-APHE with wide corrugated 'Hotchkiss style' copper driving band (this seems to be earlier than the ones with brass driving bands). Era unknown. I have one of those.
-Early APHE with wide corrugated 'Hotchkiss style' brass driving band (as shown by Ozzi). Era seems to have been around 1898 - early 1900s (at least 1901, but assumedly later too). I have three of those.
-Late APHE with wide corrugated 'Hotchkiss style' brass driving band. Showa era (i.e. 1926-1945). Has a 'normal style IJN headstamp' and normal colour style (marroon-green) projectiles with paper labels on them. I have one of those.
-APHE with 'Nordenfelt style' copper driving band. Colour (if any) unknown. I have two of those (both paintless).
-TP (APHE style) with 'Nordenfelt style' copper driving band. Colour black. Used an empty base-fuze or plug. I have two of those.
-Brass-based brass-wooden dummy. I have none of those, but I have seen them on auction.
With at least one Japanese collector I have also seen pictures of what appeared to be a nose fuzed HE 47mm projectile, but I am not sure if that was really used by the Japanese. Unconfirmed as of yet.
As for the markings: Reccetrooper gave a pretty good explanation of them, although they do have me puzzled still somewhat, and I'm quite sure the reading is not fully correct. The wavy anchor is Kure, that's correct for sure. The 'simple anchor' (as I call it) does not match the Yokosuka anchor though (which used an anchor with a 'Y' like and a straight crossbar). I have seen the 'simple' anchor on various contract cases (amongst which Dainippon and EOC). The 'inverted E' indeed reads 'yo', but in this case it appears to be an acceptance/inspection mark. It does not appear (to me, at least) to be an arsenal manufacture mark. Several of the cases I have carry this mark, as well as other letters in circles (at least an 'L' is also seen sometimes). Several other cases carry no markings. Then, yet other cases carry Kanji markings, the one most often seen is the 'Asahi' Kanji marking. To further confuse matters; all of these markings tend to appear in just about all possible permutations; making it very difficult for me to draw a line on what was manufactured where, and/or reloaded where, and/or inspected by whom... It seems most likely though, that the Kanji and 'circle' markings are inspector markings. Cf markings appear on several specimens, but not on all of them.
As for EOC: EOC marked their cases well; at least between 1898 and 1901. Apart from the above mentioned complete rounds, I have 4 spare casings too, with a variety of headstamps. The EOC ones clearly show the logo, and the month and year of manufacture. I see no EOC markings on this one. It's still somewhat of a mystery where the non-EOC marked ones were exactly manufactured, there are basically four different head styles that I know:
-EOC: Head without grooves, but with concentric circles. 12mm friction fit primer. Marked 'EOC' with dates at least between 1898 and 1901. Seen with Asahi markings and letter-in-circle markings. I'm not sure from memory if these also have Cf markings and/or anchor markings on them.
-Japanese manufactured ones (most likely Kure): Head without grooves, but sometimes with light concentric circles. Meiji era: 11mm friction fit primer. Taisho era: 13mm friction fit primer. Arsenal marked with proper arsenal anchor + date (not always present). Late Meiji and early Taisho eras (specimens in my collection range at least from 1910 until somewhere around 1916). Seem to only be marked with arsenal anchor and date.
-Unknown manufacturer: Initially assumed (by me) to be British, but perhaps more likely Japanese. Head with a single deep groove. 11mm friction fit primer. No arsenal markings (at least no typical ones). Seen with Cf markings, letter-in-circle markings and Kanji markings. And.. with the 'simple anchor' markings too (not always present).
-Japanese Showa era ones: these are easily recognisable as Japanese manufacure. They carry normal (contemporary) style IJN headstamps. Mine is from 1942.
Your casing appears to me to be of the second kind, but... there's an abundance of anchors, for which I've got no explanation. Especially not since it carries the Kure anchor twice, as well as the simple anchor! I don't know what to make of that.... Possibly manufactured by Kure, reloaded by Kure, and then twice reloaded elsewhere?!? Who knows....
Casings like these, are why I like this line of ammo so much. There are plenty of puzzles to solve still.
I hope to be able to solve some of these puzzles as I progress in my research...
One line of thought that I'm thinking of, and which I'm trying to figure out, is the following sequence of eras:
-Early manufacture (at least 1898 - 1901) by EOC for Japan.
-True Japanese manufacture in late Meiji and early Taisho, for Japan (at least 1910 (Meiji 43) - 1916 (Taisho 5)).
-True Japanese manufacture in Showa, for Japan (at least 1942, but assumedly earlier too).
That sequence can be pretty well explained with the dated headstamps. The other ones are more mysterious. They may be interrim casings, or they may even have been Japanese manufacture for Britain (!) in WW1 (probably around 1916 and later). That last assumption seems a wild one, perhaps, but it's one line of thought that Cliff Carlisle and I are thinking of strongly.
For the above reasons, I always particularly study specimens that I see of this calibre. I'm trying to figure out if indeed the Japanese went from British import to true Japanese manufacture somewhere between 1901 and 1910. I do not yet have enough specimens to close that gap, but I'm always particularly on the look out for such casings (in other IJN calibres too). So far all British manufactured casings for Japan (in any calibre) that I have seen have had a maximum date of 1901, and so far the earliest marked true Japanese ones were from 1910. In between that era Japan has seen an extensive war with Russia 1904-1905 and one would expect to see many casings from that era. One does not. I'm quite sure (from what I do and do not encounter in Japan) that almost all brass from that era was re-used later for later manufacture of brass items.
I'm very interested in closing this gap... I wonder when the British contracts ended and when true Japanese manufacture began. Also, there are so many of these casings in Britain, that either several lots were never delivered (early 1900s), or they were later exported back to Britain again (assumedly around 1916+).
Cheers,
Olafo
