We just had this discussion on another website. On a SBR, the receiver MUST be engraved if the owner is building the SBR himself on a Form 1. Engraving the barrel is does not meet the requirements for marking the maker of a SBR. The receiver is considered the firearm.
"I spoke with Mr Sanders at the ATF. If the SBR is registered on a form 1 then the name of the trust has to be inscribed on the receiver. I asked about the barrel and he said that the receiver by ATF rules is considered the firearm. If it's registered on a form 4 then no trust name is required."
When you say there has not been one case of a person being prosecute for not having it engraved, how do you know? The gentlemen that called the ATF to clarify didn't have his SBR engraved and they gave him 30 days to have it engraved and provide proof...
After going to the trouble of applying for and receiving a tax stamp on a SBR, why would you ever want to cancel it? You can by calling the ATF and inactivating the NFA portion by informing them you sold the upper and then the lower becomes a standard non-NFA weapon. OR you could just keep the lower and in the future if you want to have a SBR just put another upper on it and there would be no need to do additional anything.
Then you definitely need to read the law again. It's very clear.
(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: (followed by the caliber, model, etc info that's been posted already in this thread.)
Only the serial number has to be on receiver. Your trust info can be on the barrel per the law.