7,62x51 steel monobloc dummy, marked MS

Sorting through boixes, packed goodness knows when, I found this steel monobloc 7,62x51 dummy cartridge, it’s deeply drilled leaving thin case walls and a vestigial base. The lower part of the “case” is quite well machined but the neck and “projectile” both have visible tool-marks, the only marking is “MS” written on the neck, probably with an electric pencil.

Does anyone knows where it comes from, what it was used for and what “MS” might mean ?

Peter

Hi Peter,
I do not know, if it is related, but there was a german ammomaker named Manusaar, which used the initials MS in headstamp.
May or may not related…
Peter