Bartholomew Roberts
Moderator
There is constructive possession under the 1934 NFA. All Thompson said was that if there is a possible legal use and a possible illegal use, then the rule of lenity says that the court will assume the possessor was going to do the legal thing and not the illegal one.
However, if you have no legal use for the parts in question (example: a 1911 pistol, a 1911 shoulder stock and only a pistol barrel), that is pretty much a textbook case of what ATF considers constructive possession of an SBR.
Another common occurence that ATF also considers constructive possession of an SBR (or at least they have written letters to that effect) is as follows:
1. You have a single legally registered NFA-compliant SBR AR15.
1. You have a single non-NFA AR15 rifle.
3. You have more than one short barrelled SBR upper for the AR15.
However, if you have no legal use for the parts in question (example: a 1911 pistol, a 1911 shoulder stock and only a pistol barrel), that is pretty much a textbook case of what ATF considers constructive possession of an SBR.
Another common occurence that ATF also considers constructive possession of an SBR (or at least they have written letters to that effect) is as follows:
1. You have a single legally registered NFA-compliant SBR AR15.
1. You have a single non-NFA AR15 rifle.
3. You have more than one short barrelled SBR upper for the AR15.