Yesterday visited a museum office and an archeologist confirmed it to be a cannon ball from 1600-1700 era. Kartessi cannon. They really wanted to know where I found it cause it to be found in Espoo on an area not typically thought to be a battle field was interesting. Went again yesterday evening and found another one two meters from the first. Made a found report on the museum website and now waiting if they contact in anyway. But I didn't need to give it away and didn't deny of further digging. Gonna probably go today again.