You are missing the point. For the last time ... show me a gun manufacturer or any manufacturer for that matter that will set up a factory to make items only to be sold within one state?
They cannot legally do that right now, though Marbut intends a production run of Buckaroo .22 caliber bolt action rifles whose design is public domain, so cannot be messed with by the feds using its patent as an excuse.
His lawyers have forbidden him to even assemble a single rifle until the case is settled.
Well, he is one manufacturer who *wants* to do this, but no others can say so, without being threatened by the BATF&E.
So you can right now claim that no manufacturer would ever do so, but there is no way of proving that claim. However, lots of states are trying to make it easy for entrepreneurs to do so, so I am not inclined to agree with your opinion.