Guns have always been banned from Thingverse, although the site is largely unpoliced. But in light of the recent tragedy, Makerbot’s legal team has been cracking down, telling users who have loaded weapons components to the site they must remove them. Here’s the official language in Thingverse’s terms of service:
You agree not to use the Site or Services to collect, upload, transmit, display, or distribute any User Content (i) that…physical harm of any kind against any group or individual, promotes illegal activities or contributes to the creation of weapons.
Of course these things don’t happen over night; in a quick check I found that there are still gun parts designs on Thingverse. Although to discover them you’d have to know your stuff. Here’s a plan for a Glock magazine. Here’s another for a Ruger LCP pistol grip. But the point is that these parts are getting harder to find. You can’t just type in “gun” and get a real, usable weapon plan. And that’s a good thing, because guns made with printed parts can still be armed and used to kill just like regular guns. Makerbot hasn’t said outright that weapon purge is a reaction to Sandy Hook, but the connection is undeniable. [Forbes]
Pictures: Thingverse
If you are lucky, the plastic used by makerbots could fashion you a half decent water pistol. To fire actuall bullets, your big problem is a "barrel" which is typically machined from a compund called "steel" on a machine called a "lathe". Ban all lathes, and the sale of weapons grade steel, and you'll have a better chance of controlling gun manufacture. Not actually GOOD - just better than this idea.
Problem is, plastic parts can be used to make moulds for castings. Its not that the plastic gun can't shoot bullets but the actual design being publicly available and readily printed
You can try casting a barrel, but unless you are making an old fashioned blunderbuss, musket, or shotgun, you still need some precision cutting of the barrel insides to match the bullets.