Japanese 20x125 drill cartridge?

[DEADLINE222]

Yet again, I have proven my ability to perpetuate the acquisition of uncommon items in which the internet harbors seemingly no information pertaining to.

I assume it is a Japanese 20x125 drill cartridge utilized by the Type 97 or Ho cannon?

The threaded base screws off.

 

[US-Subs]

I've seen a couple of others, but do not remember if the base unscrewed or not, I never checked. Not sure about a reference either, but I would start with the British Ammunition Leaflets, they have the best detail and were the most accurate within what they covered. I believe small stuff was in the "B" series.

 

[Slick]

Ken Elks' book, "Japanese Ammunition, 1880-1945, Part 2, 20mm-40mm", pg. 113 & 114 makes note, with picture, of your find.