Help me with identifying old (1917) rifle cartridge

Hello. I accidentally found an old brass case in my backyard in Bulgaria, and i wont to know from what kind of ammo and what gun it came. The head is stamped with “v” on top, “19” on the left-hand side and “17” on the right-hand side, and “RM” on the bottom. Can anybody help me?

Hi kaneto,
You haven’t really provided quite enough information to make a positive identification but I am going to guess that your case is 50mm in length? If so then it is a 8mm Austrian Mannlicher made by Rheinish Metallwaren, Sommerda, Germany in 1917. I am not certain but I suspect the letter ‘V’ indicates the 5th month…May.
I can post a photo of the live cartridge if it helps you.

This poor picture show a nearly similar (III instead V) 8x50R:

And a better one of 1916:

Thank you a lot. The headstamp looks just like that on the second picture from the post of Defender.