I'm going through the same process now (starting it at least) and in Ga. I only have to register the lower. i can buy as many SBR uppers as I want but i can only attach them to the lower that is registered. At least thats how it was explained to me. I also asked about suppressors and was told that I only register the suppressor and can attach it to any of my guns (providing they fit of course).
Keep in mind, I'm just now starting the process and could easily be wrong, but registering the lower makes sense.
|