Ammunition coding technology works by laser etching the back of each bullet with an alpha-numeric serial number. Then when a potential criminal purchases a box of 9mm cartridges, the box of ammunition and the bullets’ coding numbers would be connected to the purchaser in a statewide database.
Translation: "We will register every box of ammo bought by everyone, which means if you buy ammo we'll assume you own a gun of that caliber(no ammo as gifts, that's naughty) which means, except for serial numbers(that'll come later) we'll have a list of what you own."
Again: make it as expensive(think of what that'll do to the cost of ammo and bullets) and difficult and scary as possible for people to own arms, so as to scare as many as possible into giving up their arms or scare them from getting them in the first place.
And, sure as hell, the next step is "And if the serial number on a bullet cannot be read, we'll go around to everyone in the area who has bought that type of ammo and start checking their guns; who cares about that nasty 4th Amendment stuff, when this is for public safety and(you know it'll come) For The Children?"
Think of the news story a while back from the People's Republic of Maryland about their State Police(a really apt name in some cases) showing up in full ninja gear at people's homes because "You bought ammo for a type gun that we don't have you registered as owning." Think of that same crap in your neighborhood.
Just like most early anti-gun-ownership laws in this country were race or other bigotry-based, this is also a means of controlling people. Nothing more.