Shell id....

[starshell]

Hi all,

Would anyone here have an idea what this shell fragment once was. (Found next to a pile of 7.7 minenwerfers on Hawthorn ridge)
It measures 4.5" dia (114mm in new money).
Base to beginning of threads for ogive measures 8 3/4" (225mm).
Driving band width: 20mm
Base to driving band:20mm

Initially, I thought maybe a British 4.5" How with economy band? But the shell seems too short compared to others I have.
2nd thoughts were a 12cm German HE?
Any help would be appreciated. Thanks in advance!

 

[MINENAZ16]

Hello,

Do you have a picture of the top thread ?
Markings on base are typical for 4.5in. You could clean it and see, maybe the solution (markings are usually 4.5 How and a roman number for Mark).
Different shape for 4.5in so you could have a shell with head screwed (missing) so fragment is shorter.
Thin walls could be for a 4.5 shrapnel (232mm without head). Look inside if there is a reduction for the steel disc).

Regards

 

[starshell]

Thanks Minenaz16,
Attached is a pic of the top thread. It measures 22mm high.
The only stamps I can make out is what looks like a capital M. There are other marks there but they are rusted and incomplete, so I'm unable to make them out sadly.
There is no recess for a charge cup in the base, so I'm guessing HE.
Hope this helps...
Many thanks!

 

[MINENAZ16]

ok, it's better with these photos.
External thread = typical british 4.5in with special filling, gas or white phosphorus. This shell is called "double diaphragm".
Length of body without head is near 228mm.
You have the model with economic narrow driving band.

Regards

 

[starshell]

Minenaz16,
Many thanks again!
Suprised and chuffed to find its a chemical shell. Thanks for the illustration, very helpful indeed.
And having found it in the field makes it all the more special...
Thanks and merry xmas!

 

[peteblight]

Here’s the double diaphragm that Minenaz16 spoke about.