Where is a firearm's serial number most commonly located?

The serial number of a firearm is most commonly located on the frame or receiver. This is because the frame or receiver is considered the core part of the firearm and is the part that legally constitutes the firearm itself. Manufacturers are required to engrave or stamp the serial number on this component in order to establish a unique identifier for the firearm, which aids in tracking ownership and tracing firearms in criminal investigations.

While the stock, barrel, and trigger guard may sometimes bear additional markings or identification numbers, they are not typically where the main serial number is found. The necessity for the serial number to be etched into a permanent part of the firearm helps ensure it remains identifiable throughout the firearm’s lifecycle, which is essential for regulatory compliance and public safety.