What is required for a barrel to legally classify as a rifle?

For a barrel to legally classify as a rifle, federal regulations specify that it must be longer than 16 inches. This measurement is a standard established by the National Firearms Act (NFA) to differentiate between rifles and other types of firearms, such as shotguns or pistols. When a barrel length is shorter than this criterion, it may require additional regulations, as it could be considered a short-barreled rifle (SBR), which has specific legal implications and requirements.

The option indicating that the barrel must be more than 18 inches is not accurate since 16 inches is the definitive minimum required length for a rifle barrel. Similarly, while a length of less than 30 inches may relate to the overall length of the firearm for other classifications, it does not directly pertain to the specific criteria for barrel length related to rifles. Lastly, stating an exact length of 20 inches is too restrictive; the law does not require barrels to be exactly that length to qualify as a rifle. Thus, the requirement focuses specifically on exceeding the 16-inch threshold.