Thank you very much for the question. The reason I mentioned the Firearms Act reference, the Supreme Court case, was that it's the case in which the validity of the law, in fact the federal regulation of firearms, was disputed by several provinces.
The way the Supreme Court solved this issue, and it's key to your point, was by saying that the federal government has jurisdiction to regulate personal property that is otherwise under the jurisdiction of the provincial governments, because it does so using the criminal law power. Not testifying as a constitutional expert here, but as a criminal defence lawyer, I would in fact question whether or not Parliament would be allowed to enact simple regulatory provisions regarding private property such as firearms.
The issue of firearms' owners feeling targeted by Parliament, being treated as criminals, is why they end up at my door. I'm a criminal defence lawyer and this is a strong segment of my practice.