The attached images contain a headstamp which I do not recognize (nothing unusual about that!). The round appears to be a modern .380 Revolver, perhaps a short-range or a blank. The white plastic visible at the case mouth may be a wad or a round plastic ball.
I thought the TEPEH-3 might be Cyrillic but using the equivalent Cyrillic characters got me no closer, though with the variations in the Cyrillic alphabet, I may have picked the wrong Cyrillic alphabet!
Help would be appreciated.