What is this? ? Japanese 27mm Case

Case I found on ebay this morning, can anyone tell me what it is? (See photo and link) any info would be helpful. I have never seen anything like this before.


Hi Falcon,

This is not a 27mm but a 25mm case.
It is 25mm Type 96 for Japanese navy.
This is the same case as the French 25x163mm Hotchkiss.



Cheers Rien. What was this used for? Anti Aircraft? I won’t be buying this as it is outside my area of interest, J just wondered what it was.

Yes, Anti Aircraft.

As Western said, this is for the Japanese Type 96 naval anti-aircraft gun.

It came in both brass and steel cases in a number of loads. These were explosive, explosive tracer, explosive incendiary, APT, tracer and practice as well as three types of dummy/drill. There were also variations of the above with self destruct fuses.

According to WW2 enemy weapon manuals the Type 96 had a vertical range of about 10,000 feet and a horizontal range of 5000 yards.


This was a standard Japanese medium AA gun which was often used on land mounts as well. I have the US training video for the use of these captured guns of possible interest.

Pic of the 25x163 next to some others (from the Ammunition Photo Gallery on my website):

23x115 Russian (NS-23, NR-23, AM-23, GSh-23, GSh-6-23), 23X122 (exp. French HS.406/7), 23x139SR (exp. US T4) 23x152B (Russian ZSU - VYa almost identical but brass case), 24x138 (Swiss Pzw.Kan 38), 25x137 (Oerlikon KBA: NATO standard also used in M242 Bushmaster Chain Gun, GAU-12/U, GIAT 25M811), 25x163 (Hotchkiss - aka IJN Type 96), 25x184 (Oerlikon KBB), 25x189 (Vickers 25.4mm), 25x218 (Russian Navy: earlier M1940 version used a slightly different, 25x218R, case, while the Bofors it was developed from used a 25x205R case), 27x145B (Mauser BK 27), 28x199SR (USN 1.1")

A fine reference lot for case types.