THE NATIONAL FIREARMS ACT OF 1934
This law didn’t just impose a tax on machine guns; it also defined a number of categories of regulated firearms collectively known as “NFA firearms.” Today, all serious gun owners, not just collectors, should be at least aware of these:
Machine guns—any firearm that can fire more than a single cartridge per pull of the trigger.
Both continuous, fully automatic fire and
“burst fire” (such as a three-round-burst) are considered the primary functionality in what determines if a weapon is a machine gun.
Short-barreled Rifles (SBRS)—ANY weapon that has a rifled barrel and buttstock and has a barrel fewer than 16 inches long or has an overall length that is fewer than 26 inches is considered a short-barreled rifle. This includes firearms that were manufactured with a buttstock that was removed, as well as weapons with folding buttstocks. In addition, adding a fixed buttstock to a pistol makes it an SBR.
Short-barreled Shotgun—this is similar to the SBR but includes smooth-bore barrels that are fewer than 18 inches long or have a total length of 26 inches. This would include so-called “sawed-off shotguns.”
Silencers—this includes any portable device that can be affixed to a firearm and is designed to muffle or disguise the report (sound) of a firearm. It should be noted that this does not include “non-portable” devices, such as a sound trap that could be used by a gunsmith in a shop.
Destructive Devices—this includes two broad classes. The first would include such items as explosive munitions, bombs, poison gas weapons, hand grenades, land mines and anything that would be considered a military-grade device intended to kill or maim. The second class is any firearm with a bore over .50 inch. In essence, a .50-caliber weapon is the highest-caliber weapon that can be owned by a civilian. However, some shotguns and shotgun shells that are determined to have “legitimate sporting uses” do not fall into the category of destructive devices.