You are wrong, sir. Not in the presentation of, or solution to, your argument, but primarily in the basic answer to its title: Do Gun Control Laws Control Guns? And secondarily, to your notion within that argument that "the over-riding factual question is whether gun control laws actually reduce gun crimes in general or murder rates in particular."
As with most other news and editorial pieces regarding the issue, you make valid points to rearrange deck chairs on a sinking ship. And miss the opportunity to make a more-vital point.
Start with the question in the title, Do gun laws control guns? And, instead of treating the symptoms, look at the sickness, get to the very real meat of the matter for your answer. And it is this:
Gun control is not about controlling guns. It is about controlling people.
To paraphrase your supposition, the over-riding factual question is whether the rights of government can abridge our natural rights.
I have as much respect for your political aptitude and Constitutional scholarship as I do anyone's. So, it is my hope that you will redirect your focus on the genuine issue, rather than dance around the edges like most of the other editorialists. There are plenty of folks ready to take the easy road, centering the dialog over my right to hunt and your right to fend off a burglar.
Those are valid and important uses for our guns. But they have nothing to do with the 2nd Amendment. Criminalizing guns is part of their victory. Another part of that victory is fogging the issue on the Conservative Right. Don't let that happen, please.
They'll come for my guns, and then for your voice.
It's about controlling us. You and me, both of us.
Thanks to William Grigg at Pro Libertate (with a H/T to WRSA), here's the solution to your argument. Well, not your argument, but what your argument should have been. See here: it's not the gun being controlled; it's the citizen. Regardless of his rights. Regardless of his actions. Regardless of his intent.
Dr. Sowell, we need you to keep your eye on the ball, sir.