Just a handgonne that also functions as fire lance (without the lance part).
Continue reading at my Great Ming Military blog.
By the way, my apology for the long inactivity. It's Chinese New Year, my computer (conveniently ?) broke down, and the computer service centres are closed because...well, it's Chinese New Year.
(As of now my computer is still broken, and I've pretty much given up of trying to get it repaired)