Properly Identify a Firearm for the Purpose of Tracing

Legal Definition of a Firearm

Title 18 United States Code, Chapter 44, § 921(a)(3) The term “firearm” means, in part: (A) Any weapon (including a starter gun) which will or is designed to or may readily be converted to expel a projectile by the action of an explosion; and, (B) the frame or receiver of any such weapon.

Basic Firearm Types
  • Pistol – designed to be held in one hand, short stock below line of bore, chamber integral with the barrel, double or single action, semi-automatic or single shot.
  • Revolver – designed to be held in one hand, short stock below line of bore, double or single action, breachloading chambered cylinder (top break, loading gate, swing-out cylinder, or removable cylinder loading mechanisms).
  • Rifle – designed to be fired from the shoulder, rifled bore, various types of action (semi-automatic, lever, bolt, pump, top break, or auto loading).
  • Shotgun – designed to be fired from the shoulder, smooth bore, various types of action (bolt, top break, pump, or semi-automatic), various barrel types (single, double, over/under, side-by-side).
Required Markings on Firearms

All markings must appear conspicuously on the frame, receiver, barrel or slide, except serial number which must appear on frame or receiver.

  • Serial number: Must appear on frame or receiver, cannot be duplicated by manufacturer
  • Manufacturer name, city and state (or country of manufacture if imported into U.S.)
  • Model designation (if assigned)
  • Caliber or gauge
  • Importer name, city and state (for firearms manufactured outside the U.S.)


Properly Identifying a Firearm

The most common reason for a firearm trace to fail is an invalid or incomplete firearm description. It is essential to note all visible markings on the recovered firearm and to include that information in the trace request. It is possible that a firearm may have difficult to identify markings or after-market modifications, making accurate firearms identification challenging. Please do not hesitate to contact ATF for assistance in properly identifying a recovered firearm.

Last Reviewed May 5, 2020