Really? Every time someone walks into a business establishment packing a piece, no matter how legal, is doing so without that business owner's consent.
But the First Amendment is about words and thoughts. The Second is about things. If you can restrict words and thoughts, you can restrict things. So, it is within the state's scope to restrict firearms, short of banning all of them altogether. I would submit that the simple restrictions I am advocating here would pass muster, even under the current conservative court.