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.
Well, the OP asked for my opinion and my previous post was meant to be presented as such rather than a hypothetical argument before the courts. That being said, I simply do not see SCOTUS accepting a ban on semi-automatic firearms because semi-auto passes the "common use" tests of both Miller
with flying colors.
Now, as to whether the courts would agree with me on full auto is another matter. SCOTUS already upheld the NFA in United States v. Miller
though that was a very, very unusual case and the court used a rather novel line of reasoning to get where it did. If I were to speculate, I would probably guess that neither SCOTUS nor the American people in general are to the point that they would support the repeal of the NFA, at least not yet. Turning the tide and taking back the rights that have been stripped away from us over the years is a fairly recent turn of events. There are much more pressing and easily accomplished changes that we should make before tackling the NFA and none of it is something that can be done overnight. Honestly, I'm not even sure that the NFA is something which should be addressed judicially. Perhaps attacking the NFA legislatively would be the better approach. Regardless, my comments were not meant to be a suggested plan of attack for repealing the NFA, but rather my own personal views on the matter which is what I was under the impression that the OP was asking for.