Well, it seems simple to me. The 2nd Amendment gives everyone the right to bear arms, true. It says nothing about bearing bullets. Let people buy as many guns as they want, just don't let them buy bullets. Also, the amendments says nothing about firing pins. Or firing pins. Semantically, I can think of a many ways one could get around that pesky amendment. But the very simple fact is that no politician, not one who wants to remain a politician, is going to touch the Bill of Rights. Outlawing this doesn't work either. Cocain, heroin, smack, crack, murder, grand theft auto, burglary, cuban cigars, drunk driving, all these are illegal.
The argument is, normally, if the criminal has a gun, I want one too. Why a small child need a gun, that is beyond my understanding. Please bear in mind, I am not a fan of guns, but I can understand the argument.