Damn my dreams are crushed here! My next project will be an SBR, I was thinking I would be able to change barrel lengths on it being the lower is actually what is registered.. It's kind of screwed up that they ask for a measurement, even though its illegal to have the parts on hand.. It is legal to own a pistol upper as long as you have a pistol lower for it as well, right? Even if you have another lower built and waiting for the pistol upper's tax stamp