help for medieval handgonne hand gun identification

[sioume]

Hi Folks,

Is there any body who can help me to identify this iron cast barrel?
total lenght: 24,5 cm
largest diameter : 10,5 cm
mouth diameter : 9 cm
inner diameter of the mouth : 4 cm
weight: 7,4 kg
Very great patina

Is this a early late 14 th/15 th handgonne or a signaling mortar used by boats and harbors to signal each other. They would shot a different color signal depending on what they wanted to say
I read a thread depicting such barrels and Mathlock's collection but I am not sure at all.
Is it a valuable and rare piece?
Thanks a lot
Alain