What is this? Silk mortar round cover? Translation please

[John Pen.]

Is this some kind of ordinance cover? Can some one translate please?
Thanks in advance, John

[Papa Nambu]

It's a powder bag used in artillery. There are 3 different types of loads for artillery:

Fixed, with the powder sealed in a shell casing
Semi-fixed, with a loose shell casing so the powder can be adjusted or just transported in components
Separate, with no shell casing. The projectile is rammed in the breach then powder added behind it and a primer in the breach block.

The last 2 methods both use per-measured charges of powder in combustible bags of set sizes.

Yours is for a Type 1 AT Gun http://en.wikipedia.org/wiki/Type_1_47_mm_Anti-Tank_Gun
It was made in Osaka in March 1944. The small pocket at the base held a finer powdr that was easier for the primer to set off, this in turn would set of the main charge in the bag.

[John Pen.]

Papa Nambu,
Thank-you so very much!
Cheers,
Jp