German smoothbore guns are usually "full length", meaning 40+ inch long barrels. Most are half stocked, and usually considered bird guns, but there are plenty of full stocked "general purpose" smoothbore shotguns.
There are also straight rifled guns. In the 18th century, these were called "Schrot Buechsen" (shot rifles). They are treated as smoothbores, without rifle type sights, and usually without patchboxes. They are said to make better shot patterns, and you can buy straight rifled modern shotgun barrels today. :wink:
I had a straight rifle barrel made up for me, and eventually I'll get around to stocking it.
I guess they could be used "defensively", but they didn't go around carrying rifles or shotguns. Defensive arms in 18th century Germany would be swords (either hunting swords or smallswords) or probably a walking stick (I see LOTS of use of man-tall walking sticks in 18th century German images, and I can imagine that they were considered defensive tools :wink: ) One might carry a pistol too, but they weren't real big on pistols there at the time (other than military pistols or rifled pistols for target shooting).