Which of the following would qualify as a short barrel firearm?

A short barrel firearm is defined under federal law as a weapon with a barrel length of less than 18 inches for shotguns and less than 16 inches for rifles. In this context, a shotgun with a 17-inch barrel meets the criteria for being classified as a short barrel firearm because it has a barrel length that falls below the 18-inch threshold established by the Bureau of Alcohol, Tobacco, Firearms, and Explosives (ATF).

In contrast, the other options do not qualify as short barrel firearms. A handgun with a 6-inch barrel is not considered a firearm under the same federal short barrel definitions, as handguns are generally categorized separately. A rifle with a 20-inch barrel exceeds the required maximum length for short barrel classification, thus not qualifying. Lastly, a crossbow does not fall under the category of firearms regulated in the same way as firearms with barrels, making it irrelevant to the definition of a short barrel firearm.