The test for how far a right can be reasonably regulated is how much public interest does said regulation serve vs. how much liberty does it take away. In my opinion, the current level of regulation on full auto and large-caliber weapons does not represent a large enough increase in public safety to justify the degree of liberty that it strips away.
WebleyMkV: That is closer to a workable definition, and it might convice the court. It sure leaves a lot of discretion with the court, which may not be a good thing. What if they ruled that banning semi-automatic firearms is a good balance between public interest and liberty? We can't assume that they would think the way we think.