1) There are something like 300-600 million firearms in the US. Attempts to disarm only get the guns from those who are law abiding, you disarm the defenders without doing much to the criminals.
2) You probably increase the death rate as you have made people less able to defend themselves, but done basically nothing to most murders because you didn't succeed in disarming the criminals.
By increasing the supply their availability for criminals also goes up proportionally.
This isn't common today, but considering ongoing the efforts to make 3d-printing Glock and Hi-Point frames easier I can't imagine it will remain uncommon forever. These aren't exactly hard to find, see [0].
And for those who think you can just ban all other gun parts and fix the problem, I present to you the FGC-9 - a pistol-caliber carbine manufacturable in your basement with a 3d printer, metal bar stock, and some high-pressure pipe. Semi-auto, rifled barrel - the works. [1] Is it a trivial process? No. Is it going to get easier and produce higher quality results with time? Yes.
0: https://www.defcad.com/library/60d6a735-4a8c-4b42-8dd7-33b13...
1: https://www.defcad.com/library/ac26b242-720f-4608-a202-0ecea...
In the UK and Europe, criminals modifying replicas or other close starting points is quite common.
You know where modifying guns with 3D printed parts is common? The USA, since you can turn many of the commercially available ones into automatic weapons.
People have done it, but it is not common at all.
Moreover, for the time being, 3D printed gun parts have an extremely short lifespan.
The real threat is ghost guns. It *used* to take a skilled machinist to make gun parts, but CNC machines at the home workshop level are now capable of doing it. Any reasonably competent adult can do it, you don't need to be a machinist.
Yes, those are even shorter, but even industrial 3D printers are ill-equipped to print anything other than the gun's frame. Even lower receivers are a problem.
The bolt carrier group on a long-gun does not fare well unless it is made of metal (or special ceramics, in some niche cases). Same goes for the gas-block on gas-operated guns (like AR-15s or AKs), or the lever on lever-delayed blowback systems (e.g. the LAI on the FAMAS), or the rollers on something like an MP5. The DIAS required to convert an AR-15 into a full rock-'n-roll model has to bear a lot of mechanical and thermal force as well, and the 3D printed ones are notoriously unreliable. They can chip, deform, or fray at the worst possible time, releasing the hammer. They can fail to retain the hammer, and neuter your weapon in a gunfight. Most importantly: they always do this. The good ones can barely get 100 rounds off.
Handguns and long-guns likewise need hard, heat-resistant materials for firing pins, ejectors, chambers and barrels. That's unlikely to change anytime soon, unless we suddenly discover new polymers with hardness and thermal properties on par with steel.
And here's the dirty secret: you can already buy plastic guns. They're called Glocks.
>The real threat is ghost guns. It used to take a skilled machinist to make gun parts, but CNC machines at the home workshop level are now capable of doing it. Any reasonably competent adult can do it, you don't need to be a machinist.
Any reasonably competent adult can buy an 80% lower receiver [0] and produce a fully-functioning AR-15 lower receiver with a hand-held file and a few hours of work. And this is legal. The rest can be legally purchased without any oversight, because the lower receiver is the only thing that qualifies as a gun.
3D-printed "ghost guns" are a myth invented by TV talking-heads to scare pearl-clutching soccer-moms in the 80's. The reason they are a myth is because it's cheaper, safer and easier to just build a real, usable gun that wont melt in your hands. And again: this is doable with polymer parts, too.
To reiterate, because it bears repeating: the world you fear has existed for at least 25 years.
[0] https://www.5dtactical.com/ar-15-80-lower-receivers-s/109.ht...
> a pretty good example how gun control saves lives.
It sounds like the door saved lives. He was still able to shoot people. It doesn't sound like gun control laws saved any lives; maybe the building codes did.
Especially since it sounds like his substitute gunpowder worked.
Out of approx 400,000,000 guns, only very roughly 12,000 are used in crime. There is less than 0.01% overlap.
https://health.ucdavis.edu/what-you-can-do/facts.html
If you include the number of persons shot but not killed directly you are looking at about 20x that number.
And that doesn’t include firearms used in other crimes of violence.