Help with WW2 Japanese Type 91

[Fragman]

Hi. This item was recovered by a qualified EOD technician. Any live ordnance found with it was disposed of appropriately.

This Japanese Type 91 is one of two found in an old ammunition depot. Both have what looks to be a nut cast into the well cavity in the bottom. Ive not started to clean it up yet, so have no idea if its cast or welded. Has anyone seen an example like this before?

Cheers

 

[US-Subs]

I've never seen this variation before, but it may be that what you have is not a Type 91, but an early Type 97 grenade. They Type 91 was not a grenade by function, but a mortar or piece to be fired from a "grenade discharger". Eventually it evolved into the Type 97 hand grenade, initially from converted Type 91 bodies. When they first converted the former mortars they changed the fuze, shortening the delay to about one third. To ensure that the newly converted grenade was not used by mistake in the mortar they painted the bottom white and welded spots on the circumfrence of the body so that it would not fit in the tube.

Your body looks as though the nut was fastened in place possibly for the same reason - with the nut in place the propellant charge could not be attached, so no loading into the discharger. Only a guess, but it would seem to fit the evidence.

 

[Fragman]

Hi. Thanks for your comments. That's a great looking T91 transitional grenade. Is it yours? I’d like to think the one I've got is a variation of the Type 91 transitional grenade. That’s what I’m hoping anyway. One theory I have is that it is a Type 91 body that has been modified so that it could not be used with a spigot launcher or mortar, whilst still being able to be used with the cup discharger (unlike the ones with the added body lugs). Seems feasible, logical and easier to achieve than machining away the threaded base and adding the lugs. However, if they are a manufacturers variation, why are they not more common (I only know of two having been found)? Cheers