Demonstrating how easy it is to manufacture guns with modern equipment shows the futility of trying to stop it with simple restrictions, such as the silly shipping restriction. As a related example, some people in the US think that a useful answer to gun violence is stronger rules on who can purchase guns and how they are registered/tracked. That's just ridiculous when any yahoo can whip out an unregistered gun this fast. (Our yahoos are similar to your chavs, but with even worse outfits)
The US is close to having a gun for every single citizen. It will take more than any of these "think of the children" laws to make that go away. And media hysteria here is actually leading to more gun sales. We had a spike in talk of banning "assault weapons" again a few years back, whatever that means. The only result of that was a giant increase in AR-15 sales.