How does that work when making an AR pistol. Do you have to re-certify the Lower as a pistol receiver instead of a rifle receiver?
GG, I never completed the build of the lower. The ATF says, IF, you first build it as a pistol, it is a pistol, No need to register it as an SBR and get the stamp. I checked with my FFL and he marked it in his book as "other". SO, I can legally build it as a pistol. And, I can pin a rifle upper on it and go back to pistol and that's also legal, (if I'm reading the regs correctly).
Marcus