Toy cartridge, dummy or?

Hi All

Someone can help me to ID this piece? it is made out of metallic case (brass) and non magnetic bullet, It looks a lathe machined bullet made out in some kind of polished Stainless steel.

Some dimensions:
Case length: 34,4mm
Bullet diameter: 10.3mm
Rin diameter: 13.2mm
Case diameter at the base: 11,7mm