Unknown Shrapnel Shells- HELP PLEASE ID!

[Ryan Andrew]

Unknown shrapnel shells. Both type and origin are unknown. Drive band rifling marks are unusual, I hope for someone they are a dead giveaway! Thanks for your help guys!

 

[greif]

What is the length of the shell? And the diameter measured at the threads.

 

[Ryan Andrew]

I dont have them on me, ill get back to you. Thanks

 

[Ryan Andrew]

Markings are as follows: its got an upside down triangle, followed by an "M" inside a star. Then "N & W" and 5392 at the bottom. Smaller markings incude an "X" an "AF (combined)" and a "K". The serial number is stamped just above the driveband and reads "291116". The measurements are, diameter at base: 74mm, diameter at tapered up top: 74.6mm, base to driveband: 37.52mm, thread minor diameter: 62.02mm, and overall length: 220mm. Any help appreciated.

 

[Ryan Andrew]

These are photos of the measurements and markings