100 mm plastic projectile

[Nabob]

Hallo, I am looking for ID on this 100mm plastic projectile.
The story is that it was brought by Polish forces for training during a Warsaw Pact exercise.
It used to be filled with non-freezing red liquid (recoil brake fluid?).
The arrow on the x-ray shows where the two pictures have been connected by graphic software.

Thanks, Bob

 

[Nabob]

The projectile is a "imitator strzału armatniego" for the D-10T and BS-3 guns.
Polish Army has the same for 125mm 2A46 see here: http://www.nadzagozdzonka.pl/wiadomoci/3-newsflash/5252-imitatory-z-meska-dla-twardego.html
For the Leopard 2 120mm see here http://yadda.icm.edu.pl/yadda/element/bwmeta1.element.baztech-article-PWAA-0036-0023

100-ISA was filled with water or nonfreezing liquid. danger area was 200m in front of the gun.

Bob