VERY odd japanese shell...or ? WHAT IS THIS THING?

[grimble-nibitz]

Local estate find...I cannot find ANYTHING about what this is...the cannister is painted tin, just for shipping and not a heavy shell...sleeve lid missing. Rope piece is on a threaded ring that unscrews allowing access to another rope inside the shell (?) which would be hard to pull out, its down there a bit. Engine turned threading on the bottom part, very sharp...not heavy...what the HECK is this? Partial japanese label on the army painted tin sleeve...which has a bump guard in bottom to keep whatever is inside from slamming into the end...totally stumped! Advance thanks for mystery solving!

[Dieter3]

Go here, pose the question:

http://forums.gunboards.com/forumdisplay.php?52-Firearms-Of-The-Rising-Sun