A firearm is defined as any weapon (including a starter gun) that will expel a projectile by means of an explosive—or is designed or may be readily converted to do so. This includes the frame or receiver of any such weapon, any firearm muffler or silencer, or any destructive device.

A destructive device includes any explosive, incendiary, or poison gas—(i) bomb; (ii) grenade; (iii) similar device; or (iv) any combination of parts designed or intended to be converted into a destructive device, or from which a destructive device may be readily assembled. A destructive device does not include black powder or antique type firearms. 18 U.S.C. §921(3).

It is a federal criminal offense—punishable by up to 5-10 years imprisonment, depending on the specific violation—to knowingly possess or manufacture:

• Any machine gun, fully automatic firearm, or any part designed or intended exclusively for use in such weapon;

• A firearm silencer, including any device, or part thereof, designed to silence, muffle or diminish the report of a firearm;

• A sawed-off shotgun with a barrel length of less than 18" or overall length less than 26";

• A sawed-off rifle with a barrel length of less than 16" or overall length less than 26";

• A destructive device;

• A semi-automatic assault weapon manufactured after October 1, 1993; or

• A firearm that lacks a serial number or contains an altered or obliterated serial number.

18 U.S.C. § 922(k), (o) & (v); 26 U.S.C. § 5861.

And federal firearms laws prohibit transactions in and possession of certain types of firearms. These include, for example:

• Transfer or possession of a machinegun—18 U.S.C. §922(o);

• Manufacture, importation, sale, or possession of any firearm not detectable by airport security devices—18 U.S.C. §922(p); and

• Possession of a firearm not registered as required by the National Firearms Act (NFA)—26 U.S.C. §5861(d).

In New York, a firearm is broadly defined to include any weapon that can expel a projectile by means of an explosive, as well as the frame or receiver of such a weapon, silencers, and destructive devices such as bombs and grenades. Federal law, specifically 18 U.S.C. § 921(3), provides this definition and excludes antique firearms and those that use black powder. Federal criminal offenses, with penalties ranging from 5 to 10 years imprisonment, include the possession or manufacture of machine guns, silencers, sawed-off shotguns and rifles, destructive devices, certain semi-automatic assault weapons, and firearms with altered or missing serial numbers (18 U.S.C. § 922(k), (o), & (v); 26 U.S.C. § 5861). Additionally, federal law prohibits the transfer or possession of machine guns (18 U.S.C. §922(o)), the possession of firearms undetectable by airport security (18 U.S.C. §922(p)), and the possession of unregistered firearms as required by the National Firearms Act (NFA) (26 U.S.C. §5861(d)). New York State has its own set of stringent gun laws that complement federal regulations, including the SAFE Act, which further restricts the possession of assault weapons and high-capacity magazines, and requires universal background checks for all gun sales, including private transactions.