The second amnedment is the recreation amendment. It exists to insure that future generations will be able to go hunting and target shooting. Everybody knows that.
Besides, we all know that criminals will snap to attention and obey the law for the first time in their lives.
"Hey, man, got some five-finger discounted Glocks here. Want a couple?"
"No way, bro. I already hit my quota for gun purchases this month."
If you believe gun laws will change the crime rate, you are either on the take, a fool or a lefty. All three are possible, of course.