Some of you may have heard that one of Vasco da Gama's ships, the Esmeralda, was found off the coast of Oman. They brought up a collection of arquebus barrels and I wish to make a reproduction of one of them for an experimental archaeology project. Do any of you know any good sources for casting gun barrels?

Also, The question one of the researchers is trying to ask is whether the guns would have been used by officers or seamen.
Personally I don't believe that there was any real distinction between low end and high end firearms this early on that could be observed by just looking at the barrel. The only gun that is somewhat contemporary is the hunting rifle attributed to Holy Roman Emperor Maximilian I, and It was not much different from any typical arquebus of the time (Sorry I cannot locate a picture). But, If any of you believe I am wrong, please tell me, and give sources if you can!

https://scontent.fdtw1-1.fna.fbcdn.net/hphotos-xap1/l/t31.0-8/12095153_10153583939488299_6235310530018104655_o.jpg
barrel I wish to cast

https://scontent.fdtw1-1.fna.fbcdn.net/hphotos-xat1/t31.0-8/12052661_10153583939523299_1581306812753889561_o.jpg
other barrels recovered

Wow, they're fun. Our UK casters in bronze have pretty well shut up shop (or at least pattern makers interested in doing this kind of thing have) and if it was going to be used for anything other than bench testing at distance I'd be very wary of being near anything that's so thin walled and cast when it went off. Doubt our proof houses would touch them either :-(

Best of luck with the project.

These guys used to sell arquebuses at wulflund.com;

http://www.cuzzs.cz/en/

They probably made them as well.

I would contact them for information.