Quote Originally Posted by MistWolf View Post
The Thompson case was about making a pistol or rifle from a receiver (Other Firearm) without having to register the receiver and pay the $200 tax. It was not about making a pistol from a rifle.
No it was about whether possession of a pistol, and the parts that could be used to make a rifle or SBR, constituted the making of an SBR (Constructive Possession as some would say). The court ruled no but in doing so they also stated going back and forth between the pistol and rifle was not an SBR, either.