S.B.R Trust name engraving question

[BigWaylon]

Not pertaining to the trust name but the caliber, if your lower is marked "multi" is it best to have this engraved as well? I was thinking that having it noted on the barrel would be okay but it looks like it is laser etched, don't know if that is .003 deep or not.

The firearm, when assembled, needs to have the caliber marked. This can be on the frame, receiver, barrel or pistol slide (if applicable).

.003" is roughly a sheet of paper...if your fingernail catches it, it's probably deep enough.

ETA: ATF Ruling 2013-3 is fairly clear on the engraving when using an existing firearm to make an NFA firearm.

[vandal5]

Thank you BigWaylon!