Can you SBR a polymer gun?
Does the BATFE accept engraving on a Glock or CAV lower?
I've seen a few SBR'ed Cav lowers on here but I don't remember how they were engraved.
I guess so. Here's one:
You can SBR a piece of wood if you so feel inclined. Also, I believe only the SN needs to be on metal. The rest of the engraving can be anywhere.
I've seen others post that the ATF doesn't like SBR engravings on polymer. However, in the case of the Glock, the ATF allows them to have their company name, city, and state on the polymer, so why not your own SBR engravings? If I ever SBRed a glock, I'd put the engravings on the underside of the trigger guard.
Yes you can engrave the polymer. The serial number has to be on metal but the "manufacturer" can be engraved in the plastic, that is where the info is on the New Frontier and Plum Crazy lowers. Or you can engrave the barrel and not swap lowers.
Polymer is all set. HK USC/UMP was no problem.