Arizona did that--with their passage of the Firearms Freedom Act to allow manufacturing of firearms, including full auto NFA weapons, within their state if sold only to customers within the state of Arizona. See my post at #4 on page one of this thread.
So did Montana, but both efforts are showboating by the state politicians, because the federal courts have already ruled that in-state manufacture is not the test for illegality under federal law.
The Stewart case is on point. The firearm that Stewart had was homemade, never left his house. SCOTUS order the 9th Circuit to uphold the federal firearms conviction against Stewart, using the rational of Raich. The existence of the forbidden object in civilian hands affects interstate commerce.