No, not by magic, but by decree. And no, it won't happen over night. But if you make it illegal to possess a gun, over time there will be less and less of them. What's the point of having a gun if you'll find yourself behind bars as soon as the authorities find out?!
What you suggest simply won't happen here in the US. About the best we can hope for is to ban certain classes of firearms from retail sales, institute universal background checks & encourage change in gun culture headsets.