Well, you see I live in a state that does not allow SBRs. I know I can get a .408 Chey Tac that can hit something at 2000 yards, but something that is shorter than 16 inches is going to cause me to loose my mind and become a criminal, because the 1911 .45 ACP does not have that affect on people in Washington. I digress.
Since I can purchase one, I just can't own one in my state, I have to find ways around it. And this is what I think. I could register my lower as a SBR and file the paperwork. Then get a AR pistol. When I am not in Washington, I could legally put the SBR on the lower with the butt stock. because I have a house in Idaho where SBRs are legal, I could then swap it out when I cross the state lines and still keep all my parts with me at either location. The SBR with the longer barrel would no longer be an SBR and the component of the SBR would no longer be part of an SBR because it would become part of the pistol package.
I will have to look carefully at the wording of the laws, but I think I could do it and not get in any trouble, as long as the "Pistol" Barrel never went on the rifle upper in Washington.