okay - now depending on what you want to write about. ie: the impact of 3d printed plastic guns in the usa - very little.
OR the impact of 3d printed guns in the wider world - potentially much greater.
Start with the fact that we're currently talking 99% of the manufacture of pistols. A pistol has no other purpose than to shoot other people.
It's of no use in hunting, it's 'usefullness' lies in the fact that it's easily concealable and instantly recognisable by anyone it's pointed at.
Once you disregard those who just want to make their own gun, and have no criminal purpose in mind, the main purpose for making your own gun is to avoid traceability.
Most guns can be traced either through serial numbers or the marks the barrel and firing pin leaves on both the bullet and cartridge.
It is pretty easy to make your own gun out of bits of everyday hardware, but most people don't think like that - fortunately.
So an untraceable gun made from plastic that can only really be fired a couple of times, is going to be mainly of interest to those who wish to shoot another person and get away with it.
Now in the states, this is a great idea. You can buy ammunition in most hardware stores and not require any kind of licence or identification.
Elsewhere in the world this is not necessarily the case.
In the uk you need to have a firearms licence and show it when buying rifle ammunition. Even shotgun shells can only be bought by someone with a shotgun licence.
Pistols are just banned. Only the people who target shot them cared when they were banned. Everybody else didn't need one or want one.
So making your own gun in the uk is pretty pointless. You can't buy ammunition for it legally and reliable ammunition is harder to make from scratch than the gun.
And if you already know where to buy illegal ammunition then you probably also know where to get an illegal firearm and won't need to print one anyway.
It is also illegal to print a firearm in the uk. If you are a criminal and have access to illegal ammunition then a cheap, untraceable and disposable gun becomes an attractive proposition. So again, while some of us might like to print the thing as an exercise in printing - nobody really cares that we can't, without risking prosecution.
I've thought about it - but why bother, I wouldn't be able to shoot it, and I could lose my printer and face criminal prosecution as a consequence.
I actually do have a current project to do the cad design for a pin fire cartridge for an old shotgun. But that's for someone who has all the licences you could wish for and is a serious historical gun collector.
Once I've got the design right, I'll print a couple sample palstic cartridges and we'll see about getting them made through a metal printing bureau.
Now back in the states where guns are treated as toys and fun for all the family. There are different considerations.
Psychologically the american views guns from an entirely different angle than the majority of the rest of the world.
You can legally buy and own a handgun in many states, so why not be able to make your own ?
And we're back to traceability. That and the simple fact that an all plastic gun is likely to literally blow up in your face.
Which is why any sensible design would include a metal barrel, even a simple tube from the hardware shop can be made suitable with the right modifications - which I'm not going to go into, for obvious reasons.
However if you leave home printers and instead enter the world of metal 3d printing. You've got a whole new set of considerations.
A metal powder deposition laser sintering printer, can not only make a fully metal gun, but one every bit as durable and practical as a conventional factory produce firearm.
And that's where you're going to have to see some new legislation.
The potential for someone to start making quality metal guns - untraceable by current methods - cheaply and with very little knowlege required other than how to use the printer, has numerous implications.
At the moment people are tightly focussed on plastic guns that are inaccurate and likely to break during use. But with metal printing getting cheaper and more widespread, that's where the future problems are going to occur.
Homemade ammunition - metal cartridge cases - can be printed to tight specification in a metal printer. And even in the uk you can still buy the materials to make both gunpowder and nitrocellulose (the original smokeless powder) without any problems.
So forget homemade plastic guns - they're a dangerous gimmick at best - but industrially printed metal guns - they will become a reality in the next few years and one that will be much harder to stop.
Gun running simply won't be necessary. Stick a couple of printers in a shed and start making the guns in the country you want to sell them in.
Want to be an arms dealer ?
spend $20,000 on a metal printer and start printing your own. The cheap plastic machine can be used for stocks and any non-metal parts.
The designs for kalashnikoff rifles are about as widespread and simplified as a gun's design can be and shouldn't pose any problems to even the cheapest metal printer.
Likewise all modern firearms currently exist as cad designs. So even that aspect is already covered.
Just bear in mind that the states is totally untypical on a global scale.
Pretty much the rest of the world treats guns as a tool, not as a toy or an indelible part of their national identity.
Americans often mistakenly believe that guns are rare in the uk. Not so, you just need a reason to own one, and then you need a licence. But if you want one, you can have one - you just need to want it for a reason, and be able to prove that reason.
The vast majority of the population don't need one and don't want one.
And that 'don't want one' approach is what generally confuses the average american.
Brits don't want a gun because they don't need a gun.
Very few americans can understand that. And very few brits can understand why americans want guns they don't need.
That and the english language are the two biggest differences between our two peoples.
Criminals can only really own illegal guns in the uk. And that's been the case for a fairly long time. And they're not easy to get hold of. While I could easily make my own gun, I have absolutely no idea how you go about obtaining one illegally.
Metal printed guns could change that, I don't see it happening in the uk. We're just not a gun oriented culture, even our criminals don't immediately gravitate towards them.
But once something has been proved doable - someone will always do it.
In the states the advent of quality and untraceable metal printed guns could have a definite impact. Particularly when you realise that you're not limited to simple pistols. But can print almost the whole gamut of man portable firearms.
And that's the scary future of cheap metal printers.
Anyway, I hope that's given you a couple of different angles to use in your dissertation.
It's interesting that until I started typing this I hadn't considered metal printers and guns. But now, well that's quite possibly the future of firearms manufacture anyway - legally and illegally.