These blocks must be completed with the firearm(s) information. All firearms manufactured or made after 1968 by Federal firearms licensees should be marked with a licensee’s serial number. Should you acquire a firearm that is legally not marked with a serial number (i.e., certain pre-1968 firearms); you may answer question 3 with “NSN” (No Serial Number), “N/A” or “None.” Unless already properly marked by another licensee, licensees who take a privately made firearm (PMF) into inventory are required to mark the PMF with an individual serial number that begins with the FFL’s abbreviated license number, which is the first three and last five digits, as a prefix to a unique identification number, followed by a hyphen, e.g., 12345678-unique identification number.
If more than three firearms are involved in a transaction, please provide the information required by Section A, Questions 1-5, on ATF Form 5300.9A, Firearms Transaction Record Continuation Sheet. The completed Form 5300.9A must be attached to this ATF Form 4473.
Types of firearms include, but are not limited to: pistol, revolver, rifle, shotgun, receiver, frame, and firearms that are neither handguns nor long guns (rifles or shotguns), such as firearms having a pistol grip that expel a shotgun shell (pistol grip firearm) or NFA firearms (machinegun, silencer, short-barreled shotgun, short-barreled rifle, destructive device, or “any other weapon”).
Additional firearms purchases by the same transferee/buyer may not be added to the form after the transferor/seller has signed and dated it. A transferee/buyer who wishes to acquire additional firearms after the transferor/seller has signed and dated the form must complete a new ATF Form 4473 and undergo a new NICS check.