I should research this barrel beter before posting, but i am just to proud to resist.
This brass haquebut is of Bohemian type, about 1440s.
In the Park Museum in Varna Bulgaria there are two iron barrels of a very similar make.
The length of my haquebut is 62,3cm with a 65mm hook and a 17mm bore and a 35mm socket hole diameter.
It was found in Croatia which was at that time a union Kindom with the Hungarian empire. The barrel could have been used in the Crusade of Varna in the year 1443-44.
Interesting thing is... IT MIGHT BE LOADED!!! I tried to feel the dept of the bore and came 18cm short to the touch hole. There seems to be lead inside the bore, but i won't know for sure until my borescoop arrives.
At this time the Hungarian King had died and his son soon followed. It was decided that king Władysław III of Poland was to rule the Hungarian kingdom. Władysław took up arms against Murad II of the Ottoman empire and marched to war. The crusader army was defeated at the Battle of Zlatitsa, but managaed to capture the son in law of the Sultan when in retreat. Murad did not want to pursue the war and was pressured into negotiating a treaty to secure the release of his son in law. Murad retired and appointed his own son, of 12 years old, to be his successor. Shortly after all the short-term requirements of the treaty were fulfilled, the Hungarians and their allies resumed the crusade. Murad was called back to lead the Ottoman army. On 10 November 1444 the two armies clashed at the Battle of Varna (near the Black Sea fortress of Varna, Bulgaria). The Ottomans won a decisive victory despite heavy losses, while the crusaders lost their King and over 15,000 men.