Undetectable Firearms Act of 1988 - Amends the Federal criminal code to make it unlawful to manufacture, import, sell, ship, deliver, possess, transfer, or receive any firearm: (1) which is not as detectable as the Security Exemplar (after the removal of grips, stocks, and magazines) by walk-through metal detectors calibrated and operated to detect the Exemplar; or (2) of which any major component, when subjected to inspection by x-ray machines commonly used at airports, does not generate an image that accurately depicts the shape of the component.

Defines the term "Security Exemplar" to mean an object that is suitable for testing and calibrating metal detectors and is, during the 12-month period beginning on the date of enactment of this Act, constructed of 3.7 ounces of stainless steel in a shape resembling a handgun. Directs the Secretary of the Treasury, at the close of such 12-month period and at appropriate times thereafter, to promulgate regulations to permit the manufacture, importation, sale, shipment, delivery, possession, transfer, or receipt of firearms that are as detectable as a security exemplar which contains 3.7 ounces of stainless steel or such lesser amount as is detectable in view of advances in state-of-the-art developments in weapons detection technology.

States that no provision of this Act shall not apply to: (1) the manufacture, possession, transfer, receipt, shipment, or delivery of a firearm by a licensed manufacturer for the purpose of examining and testing such firearm to determine whether it would be prohibited by this Act; and (2) any firearm which has been certified by the Secretary of Defense or the Director of Central Intelligence as necessary for military or intelligence applications and is manufactured for and sold exclusively to military or intelligence agencies of the United States.

Permits the conditional importation of firearms for the purpose of examination and testing to determine whether the importation of such firearms will be allowed under this Act.

Provides an exemption from such prohibition for any firearm possessed in the United States before the enactment of this Act.

Provides criminal penalties for violations of this Act.

Prohibits the Secretary from authorizing the importation of undetectable firearms.

Directs the Administrator of the Federal Aviation Administration to conduct research to improve the effectiveness of airport security metal detectors and airport security x-ray systems.

Directs the Attorney General, the Secretary, and the Secretary of Transportation to conduct studies to identify available equipment capable of detecting the Security Exemplar while distinguishing innocuous metal objects.

Repeals such prohibition ten years after the effective date of this Act.

Undetectable Firearms Act of 1988 - Amends the Federal criminal code to make it unlawful to manufacture, assemble, import, sell, ship, or deliver (or knowingly possess, transfer, or receive) any firearm which is not: (1) as detectable as the Minimum Security Standard Exemplar (after the removal of grips, stocks, and magazines) by walk-through metal detectors calibrated to detect the Exemplar; or (2) detectable by airport cabinet x-ray systems. States that nothing in this Act shall require the Federal Aviation Administration (FAA) to utilize the Minimum Security Standard Exemplar as an FAA detection standard.

Defines the term "Minimum Security Standard Exemplar" to mean a firearm substitute used for testing that resembles a revolver, is made of stainless steel, and weighs 3.7 ounces.

Prohibits the Secretary of the Treasury from authorizing the importation of undetectable firearms.

Directs the Administrator of the FAA to conduct research to improve the effectiveness of airport security metal detectors and airport security x-ray systems.

Allows the Secretary, when appropriate because of changed technology, to promulgate regulations to amend the definition of Minimum Security Standard Exemplar. Prohibits the Secretary from amending such definition so as to increase the weight of the Exemplar as set forth in this Act.

Permits the conditional importation of firearms for the purpose of examiniation and testing to determine whether the importation of such firearms will be allowed under this Act.

Directs the Attorney General, the Secretary, and the Secretary of Transportation to conduct studies to identify available equipment capable of detecting the Minimum Security Standard Exemplar while distinguishing innocuous metal objects.

Provides increased criminal penalties for using or carrying an undetectable firearm during the commission of a crime of violence or a drug trafficking crime.

Provides for the imposition of mandatory criminal penalties for using or carrying a firearm while assaulting a Federal officer.

Makes it unlawful to knowingly possess, or attempt to possess, a firearm or dangerous weapon in a Federal courthouse.

Makes it a Federal criminal offense to possess explosives in FAA regulated airports. Increases the criminal penalties for possessing explosives in Government buildings.

Increases the criminal penalties for using fire or explosives to commit, or carrying an explosive during the commission of, a Federal felony.

Prohibits the transfer of firearms to any person who does not reside in the State in which the transferor resides.

Makes it unlawful to traffic in stolen firearms (or firearms which have had their serial numbers altered) which have been shipped or transported in interstate or foreign commerce.

Makes it unlawful to manufacture, enter into commerce, ship, transfer, or receive any toy or imitation firearm which does not have markings which make it readily identifiable.

Terrorist Firearms Detection Act of 1988 - Amends the Federal criminal code to prohibit the manufacture, importation, sale, transfer, or possession of plastic firearms. Defines the term "plastic firearms" to mean any firearm: (1) containing less than 3.7 ounces of electromagnetically detectable metal; or (2) of which any major component, when subjected to inspection by x-ray machines commonly used at airports, does not generate an image that accurately depicts the shape of the component.

States that no provision of this Act shall apply to conduct by or under the authority of the Federal or State governments.

Provides an exemption from such prohibition for any firearm possessed in the United States before the enactment of this Act.

Requires the Secretary of the Treasury to submit biennial reports to the Congress regarding the state of the art of firearm manufacture and firearm detection technology.

Repeals such prohibition five years after the effective date of this Act.

Terrorist Firearms Detection Act of 1988 - Amends the Federal criminal code to prohibit the manufacture, importation, sale, transfer, or possession of plastic firearms. Defines the term "plastic firearms" to mean any firearm: (1) containing less than 3.7 ounces of electromagnetically detectable metal; or (2) of which any major component, when subjected to inspection by x-ray machines commonly used at airports, does not generate an image that accurately depicts the shape of the component.

States that no provision of this Act shall apply to conduct by or under the authority of the Federal or State governments.

Provides an exemption from such prohibition for any firearm possessed in the United States before the enactment of this Act.

Requires the Secretary of the Treasury to submit biennial reports to the Congress regarding the state of the art of firearm manufacture and firearm detection technology.

Repeals such prohibition five years after the effective date of this Act.

Terrorist Firearms Detection Act of 1988 - Amends the Federal criminal code to prohibit the manufacture, importation, sale, transfer, or possession of plastic firearms. Defines the term "plastic firearm" to mean any firearm: (1) containing less than 3.7 ounces of metal; or (2) of which any major component, when subjected to inspection by x-ray machines commonly used at airports, does not generate an image that accurately depicts the shape of the component.

States that no provision of this Act shall apply to conduct by or under the authority of the Federal or State governments. Provides an exemption from such prohibition for any firearm possessed in the United States before the enactment of this Act.

Requires the Secretary of the Treasury to submit biennial reports to the Congress regarding the state of the art of firearm manufacture and firearm detection technology.

Repeals such prohibition five years after the effective date of this Act.