Within the confines of our Constitution, which has been well-interpreted by the fine, honorable justices of our Supreme Court, how would you stop the violent, law-breaking gang member from getting firearms?
Plus the law at all levels, as well as pretty much everyone but I suppose the criminal class, supports making it illegal for a "violent, law-breaking gang member" to possess a firearm if he's been convicted of a violent felony (well, any felony, but we all agree about the violent ones).
During prohibition, it was much harder (and more expensive) to get beer (or liquor), and more liquor than beer was consumed at a considerably higher price. One outcome was significantly lower alcohol consumption and all that that means (lower deaths by cirrhosis, lower city drunkenness arrests).
If we take prohibition as an analogy, then sure, a dedicated criminal will still be able to get guns. However, a casual street-level criminal is going to have to work harder to get them because they're no longer available in the mall or from the pawn shop, and he's going to have to pay ten times as much to get one from Benny in the pool hall. That'll significantly reduce the number of guns out there, and that is what creates the environment and the expectation that results in cops shooting civilians.
Almost every appellate court below does in some capacity.
As does the original text of the Second Amendment (as you said.)
But again, how are you going to stop violent gang members from getting firearms without infringing on the law abiding?
Why not focus on the problem: rehabilitating the violent individuals + improving mental health, instead of hoplophobic, knee-jerk legislation.
Hasn't and won't in the foreseeable future come up for 5-6th, 8th, and 10-11th circuits. So with the score currently 1-4 at the appellate level and 0-4 with the Supremes, I don't find the Federal legal situation at all encouraging, since there's no state that forbids all unloaded movements of guns, I don't see much wiggle room for your "in some capacity".
I don't dispute that some people may own illegal firearms, but its by no means an endemic problem. Somebody getting shot in the UK is guaranteed to make the news. Just the presence of a criminal with a gun will interrupt live news channels, that's how rare it is.
While I don't doubt that the knowledge of who to talk to and where to go to get a gun is present in certain UK communities, the basic fact that everybody involved in procuring, handling and importing guns is committing a criminal act certainly acts as a pretty solid prevention mechanism to stop, say, an angry 20-something man from acquiring sufficient guns and ammo to go on a shooting rampage at a college.
I can go to one of those countries with strong gun control right now and turn a formidable firearm if you like - do they need better mill control?
So if you do lock your house doors when you go out, you're implicitly agreeing that you do this to make it more difficult for someone to get inside your house, reducing the likelihood of theft.
Same thing with guns.
So America has zero house burglary?
Parent claims guns shouldn't be restricted since someone can make one on a lathe if they cannot buy one at a store.
Meanwhile parent almost certainly locks their house doors despite a thief with crowbar being able to bypass their lock.
Therefore, the parent's reasoning that gun control won't work because a criminal can mill their own gun is not logically sound.
I'm going to go out on a limb and claim murders are not an opportunistic crime. People are not killing because they can and can get away with it. The comparison you are trying to make dies there because the type of crime is not comparable.
Since someone can physically go and mill a gun, should that be the reason not to enact gun control? Seems like a ridiculous reason to me, but apparently is a core bit of logic for the gun crowd.