Bomb tail fin or something completely different

[Ruuti]

Found a strange tail in the forest yesterday (and a paper punch).
Where has a tail like this been used? Roughly made to be part of a bomb…
I'll post more pictures and measurements later if needed.

 

[Dreamk]

If you found this in Finland, a good candidate could be this one:
The 3kg incendiary Elektron Bomb M38



or one of these - a series of small bomb (2kg to 25kg) produced by Tolvan in the mid 1930s