serializing an 80% ar pistol build

[Sam .223]

i just built an ar pistol out of an 80% reciever, i was thinking about putting a seal number on it just so i can avoid issues with the authority figures out there. my question is is there a specific way or template that needs to be followed? i was thinking about engraveing it under the pistol grip on the reciever so its not visible but there is still a number there.

[tal3nt]

I know it needs to be a certain depth. From what I remember though the depth requirement isn't all that much and is achieved by most engraving services.. as far as the location goes, if the whole point is avoiding issues with LE, then wouldn't you want it somewhere easily visible where you wouldn't have to remove the pistol grip just to reveal your serial to police/etc..?

[Intimid8tor]

If you are trying to follow atf refs the. It should be somewhere visible without disassembling the firearm. I would think the front of the mag well if you want it hidden. As for size, google nfa engraving to get the specs.

[Arkangel]

Courtesy of a more knowledgeable Calgunner:

Federal laws/regulations...

27 CFR 479.102
(a) You, as a manufacturer, importer, or maker of a firearm, must legibly identify the firearm as follows:
(1) By engraving, casting, stamping (impressing), or otherwise conspicuously placing or causing to be engraved, cast, stamped (impressed) or placed on the frame or receiver thereof an individual serial number. The serial number must be placed in a manner not susceptible of being readily obliterated, altered, or removed, and must not duplicate any serial number placed by you on any other firearm. For firearms manufactured, imported, or made on and after January 30, 2002, the engraving, casting, or stamping (impressing) of the serial number must be to a minimum depth of .003 inch and in a print size no smaller than 1/16 inch; and
(2) By engraving, casting, stamping (impressing), or otherwise conspicuously placing or causing to be engraved, cast, stamped (impressed), or placed on the frame, receiver, or barrel thereof certain additional information. This information must be placed in a manner not susceptible of being readily obliterated, altered or removed. For firearms manufactured, imported, or made on and after January 30, 2002, the engraving, casting, or stamping (impressing) of this information must be to a minimum depth of .003 inch. The additional information includes:
(i) The model, if such designation has been made;
(ii) The caliber or gauge;
(iii) Your name (or recognized abbreviation) and also, when applicable, the name of the foreign manufacturer or maker;
(iv) In the case of a domestically made firearm, the city and State (or recognized abbreviation thereof) where you as the manufacturer maintain your place of business, or where you, as the maker, made the firearm; and
(v) In the case of an imported firearm, the name of the country in which it was manufactured and the city and State (or recognized abbreviation thereof) where you as the importer maintain your place of business. For additional requirements relating to imported firearms, see Customs regulations at 19 CFR part 134.
(b) The depth of all markings required by this section will be measured from the flat surface of the metal and not the peaks or ridges. The height of serial numbers required by paragraph (a)(1) of this section will be measured as the distance between the latitudinal ends of the character impression bottoms (bases).

[Quiet]

You are not required to register any firearms you build yourself for personal use.

However, if you are going to do it and/or if you sell it in the future, you will need to engrave the following info onto your home built firearm.

Required info:
Make (your name)
Location of where the firearm was made (city/state)
Model
Caliber
Serial Number

Engravings need to have a minimum depth of 0.003" and need to be no smaller than a print size of 1/16".

The engraved info will be needed for the Firearm Ownership Record, which you will need to complete and send to CA DOJ BOF along with the required fees, in order to register your home built firearm.

[Sam .223]

i have no plans to sell, i just want something on the reciever that so i can say heres the number if its called into question by LE. so if i understand this correctly i can't just install a number, i need the all the info on there as well.