Can anyone here help with these Japanese markings please?


I purchased a Japanese round for my collection,and the case has markings which I can’t decipher,apart from the anchor mark which signifies Naval use.

Is there anyone here who can actually read these markings and tell me what they mean please?

I’m keen to know what year the case was manufactured.

Kind regards,

  • What is the caliber and how tall is the shell case??? Is it rimmed??? Liviu 03/01/07



It’s 47mm,length is 131mm and it is rimmed.

Kind regards,


Anyone, please?

  • Andy, in your headstamp picture I only can see 3 markings. Are these 3 markings the only one stamped on the case head??? I have a Japanese 25X163 fired brass case which seems to have one mark like I can see in your photo. I’m familiar with the WW2 Japanese arsenal markings stamped on the shell cases head but I cannot see anything from your photo. Liviu 03/02/07


Hi Liviu,

Thanks for your reply.

There is another stamp which isn’t clear in the picture.

It’s the letter E inside a circle,it’s at 6 o’clock on the pic.

Kind regards,


I am tempted to say that the one visible complex Japanese Character is “Showa.” It looks a little different than how it appears on firearms (Type 14 pistols), but the basic strokes are there. “Seal writing” or the characters used with metal die stamps, etc., are often simplified from the way they would be formally written by a scholar. Usually, in Japanese, a plain cross is the numeral ten, but that cross doesn’t look anything like a Japanese “ten” as normally stamped, and is not even really oriented right. It seems quite crude in execution compared to the anchor and the other character. In the shadows, I can make out a huge circle with what appears to be several lines inside it. Have no clue what that means. “Translation of Japanese Ordnance Markings”, August 1945, A.S.F. Office of the Chief of Ordnance, Washington D.C., was not much help, even though it has hundreds of characters and combinations that appear on ordnance. A better photo would probably be helpful, but not to me. I note a new thread on the Forum on Japanese boxes, and the person who submitted it appears to have access to a translator. Perhaps he can help here? Why not try a PM to him to get his attention to this thread?


Hi John,

It is the letter E inside the circle.

Kind regards,


Hi, The guy that does the translating is in Japan on business right now. When he gets back I will show him your post and I’m sure he will be glad to help.

John, do you have access to “Translation of Japanese Ordnance Markings”, August 1945, A.S.F. Office of the Chief of Ordnance, Washington D.C.? I would love to find a copy. Does it shed any light on the meaning of the
16 Tsuchinoe line ? We have found this line on many ammo boxes both rifle and pistol ammo. Tsuchinoe is normally translated as one of three calender signs, but it don’t make sense in this context.

  • Andy, it is very important for you to observe that “anchor” stamp. I cannot be 100% sure [just looking to your photo] but the anchor from your headstamp may show Toyokawa Naval Base. According with the anchor symbol the meaning is: A] a double wave stands for Kure Naval Arsenal; B] the letter “M” stands for Maizuru Naval Arsenal; C] the letter “S” stands for Sasebo Naval Arsenal; D] the letter “T” stands for Toyokawa Naval Arsenal; E] the letter “Y” stands for Yokosuka Naval Arsenal. These symbols appear on each anchor with the meaning mentioned above. — I have a fired Japanese brass shell case 25X163 and one of the headstamp markings is “S 6/17” which tells me this: “S” stands for “Sasebo” Naval Base and “6/17” is the date of the shell case [manufacture or acceptance] that is June 1942 [“6” is the sixth month of the year and “17” is the 17th year of Showa, 1942]. The dates during the period of reign of the late Emperor Hirohito are counted from his date of accession and we must add 1925 to the Showa year. In the case with my 25X163 shell the year 1942 comes from 1925 + 17 = 1942. For example the year 1980 is “Showa55” which comes from 1925 + 55 = 1980. Liviu 03/02/07


It has been mentioned on another forum that the E in the circle is Japanese for 3,and that the kanji symbol (top right) can be used with other characters to make a name,probably an abbreviation for the manufacturer.

Also had the Yokosuka arsenal suggested,don’t know if that was from the kanji or the x type symbol!

Don’t know how true this is!
Thanks for all the help,any more suggestions welcome!

Kind regards,