I am not trying to be a knowitall, but i do this for a living, we are not a bad name gun store.( shooters ) but i have listed a complete pistol lower as a handgun on a 4473, as per our store sop.other stores may do it diffrent ( stripped lower ). But on a complete pistol lower , parts kit installed, buffer tube installed it is a pistol lower unless you change the buffer tube. Again sorry for the hijack on the other post.