Fire Lances

[Andi]

Or it could be an object similar to the two tar lances from Emden Arsenal in Lower Saxony, Germany from the 16th or 17th century. (Photo earlier posted by Matchlock)

Even the multibarry object of the second image taken from Hartliebs: Kriegsbuch / Konrad Kyesers Bellifortis of 1411 from Österreichische Nationalbibliothek Wien Cod. 3069 seems to me to be more likely a fire lance than a multibarrel handgonne.