Does it matters as to what the previous/first/any configuration was in regards to a 4473 and what it is transferred as? Isn't any non-barreled receiver an "other"? I am pretty sure the ATF has been explicitly clear about this for several years.
There's also that whole matter about whether an AR lower is actually a firearm or not anyways. I believe that question is still hanging out there.
There's also that whole matter about whether an AR lower is actually a firearm or not anyways. I believe that question is still hanging out there.