Have you ever made or used one? For the record, neither have I, but in the rural environment I grew up in, it was common 50 years ago to make them for poaching purposes, so I heard a lot of stories and spoke to many people who have made or used home-made ones.
For one, while it's not 'hard' in the same sense that writing an OS isn't 'hard' (after all, it's a widely studied design, many have been made/written, there is much information available, so how hard can it be to write an OS, really?), it still requires tools that aren't that commonly available (a lathe, for example - how many people do you know that have one and would be willing to make a class 3 device with it?).
But also, the home made ones aren't that good. Yes, you can make a silencer for a .22LR good enough to not be heard several miles away when you're hunting at night. But those purposes are very different from silencing a caliber powerful enough to be used against humans; meaning at the least a .38 but preferably 9mm. Furthermore it's not so easy to affix silencers to hand guns and still have the gun be concealable, you have problems with semi-auto weapons to get the next bullet into the chamber, etc etc.
So, all in all, having to use silencers, even if they would work 100%, would still cause a significant barrier for perpetrating gun crimes.
One of the primary business activities of street gangs are selling drugs smuggled in from Latin America. Do you really think that it's a stretch for them to import illegal gun accessories?
I think you severely overestimate the resources of most criminals. The majority are not the criminal masterminds you make them out to be. If they were that smart they would be doing something else.
And most of the market for weapons flow South; drugs flow north.
> And most of the market for weapons flow South; drugs flow north.
Oh really? "Weapons from the north" are semi-autos. They have autos. (No, they're not convertible.) They get them from their military (which is supplied by the US) and similar sources.
A source that says "x% of traced" doesn't tell you how they decided to trace. (Hint - they have an agenda.)
It's a side point, but many semi-automatic weapons can in fact be converted to fully-automatic mode with drop-in parts. Makes sense; if you think about it, it's actually harder to make an auto stop firing after the first round.[0] Manufacturers do take steps to make the parts incompatible, but only with limited success.
Of course those drop-in parts themselves are considered to be machine guns by the ATF, and are thus absurdly expensive and hard to get ahold of. A fully legal and transferrable drop-in auto sear[1] for an AR-15, which is a few ounces of machined steel that lets you use the automatic M-16 parts, would have had to be made before 1986, and these days goes for >$5000.
[0] See http://en.wikipedia.org/wiki/Sputter_Gun . The ATF's original definition of a machine gun was a firearm which shoots more than once with a single trigger pull. Someone entirely too clever for his own good came up with the idea of making a gun with no trigger, which fired continuously so long as it was loaded. These were, for a brief period, completely legal to build and sell (although none were sold).
[1] http://www.quarterbore.com/nfa/dias.html . See also the Lightning Link, http://www.quarterbore.com/nfa/lightninglink.html which is literally just a couple of interlocking strips of metal. Cutting a strip of metal in that way is a Federal felony that can nab you >10 years even if you do not possess the actual rifle. They really do take this stuff very seriously.
If they are getting weapons from the military (and they probably are as well since the Zetas are ex military) then why are they smuggling in from the US? [1]
This is a good point, but as my sibling points out there are suppressors and there are suppressors. It's certainly well in the ability of a competent amateur to make an effective suppressor for .22LR -- I understand you can use PVC or such materials -- but try that with a larger caliber and it'll take your finger off with a decidedly non-silent noise.
You're going to need a lathe, at least -- a machine shop would be better. Even if you copy an existing design (the science is mostly understood, but it's still easier to make one that doesn't work than one that does), the metallurgy is important-- you really need someone who knows what they're doing.
And that person had better hope that no one outside of the crew knows that they know what they're doing, because as soon as those off-brand suppressors start showing up on the streets, finding that person will become the number one priority for a number of very highly trained forensic experts. They really do take this stuff very seriously.
