Unknow Japanese tool

[Anton]

Hello !
This till was found in this year at our last expedition.
This is in machine gun tool box. What it use for ?
Thank’s for looking.

[beretta1934]

This is a broken shell extractor. If the fired shell gets its base ripped off during extraction then all that is left is a brass "tube"in the breach area.
To "extract" the now rimless casing the operator inserts the tools tapered end, with the external ribs on it, into the breach. Then inner "pin" is pushed in - which expands the extractor tool walls till the ribbed portion at the end makes contact with the inner brass walls of the cartridge and the ribs get "a bite" into the shell/casing material. Then the whole assembly is pulled out bringing the cartridge remains with it.

The other portion is basically the handle to reach into a hard to access area of the Type 92 HMG.

Here is a photo of the same basic tool but for the Type 99/96 LMG.
In the upper photo the "pin" is fully out. In the lower photo the pin has been fully pushed "in" so the ribbed out section is expanded to engage the inner walls of a broken cartridge

[Anton]

Hello !
Thank’s for you help. This tool really blow my mind
Regards, Anton