As with all things kiked, the law about gun making can be read many ways. The idea is that "if you are in the business of selling guns" then an FFL and serialization is needed. If you build your own gun from a block of aluminum and your friend wants to buy it, not an issue unless you start selling a bunch. With private sales, there is still a lot of gray areas, and I'm sure fuckhead cuntmilla and sleepy joe will start to crack down on all of that.