The so calleded Mörkö handgonne, from Sweden. A medieval <a href="https://en.wikipedia.org/wiki/Hand_cannon" class="extiw" title="w:Hand cannon">hand cannon</a> of casted bronze. Calibre 21 mm. Found by a fisherman in the Baltic Sea at the coast of Södermansland near Nynäs before 1828. Decorated with a fully plastic bearded mans head above the touch hole and a religous inscription in gothic minuscle MARIA several times.
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<a href="//commons.wikimedia.org/wiki/User:Sven_Rosborn" title="User:Sven Rosborn">Sven Rosborn</a>