[Blood of Tyrants]

The firing pin is the only metal piece required and it is made from a standard wood nail.

Sounds like a good way to get seriously hurt. There is no way that a plastic bolt on a plastic receiver would be anywhere near strong enough to safely fire anything more powerful than a .22 lr.

[varyouga]

This is a simple handgun with a very thick plastic barrel. If thick enough, it can work and have a considerable safety factor. The only issue I see is that the bullet will scratch the barrel each time and make it loose. Eventually the pressure behind the bullet will get too low. The barrels are small, cheap and interchangeable so replacing it is not an issue.

If they can get a plastic barrel to fire a few dozen shots, I foresee a semi-auto model in the near future. Basically a single-use semi-auto pistol that you can throw away.

They tested it successfully with .380 several times. After first testing it from behind glass, the site's founder was confident enough to shoot it with his bare hands.