They didn't actually make a whole gun yet. They've only been making the lower receiver for the AR-15. The lower receiver doesn't take as much of a beating as the upper receiver does, when firing; it is only a housing for the magazine and trigger group.
They have one that I read took over 600+ rounds and didn't break or anything.
The full 3d-printed gun which Cody does talk about, he suggests that it would only be able to fire one or more rounds before it was no longer usable; however, they didn't even have one made at the time.
I think if people really wanted to look into making their own guns, then they should look into the works of P.A. Luty.