The germans and austrian often build unusual an "strange" guns when they attend their masterletter as an gunsmith. But they are still building hammer singles,drillings,fierlings and funflings today but probably an 10 bore would only be built after order. They have a realy long tradition building the stranges guns, just check out the Karl Hauptman guns att holts. And they are almost ordinary rifles in germany, that will say when you got the money to by from a gunsmith.