As i said upthread, registering for a license is very strict, and the categories of license dictate the type of weapons you can have. But individual weapons and accessories are not tracked or registered beyond initial point of sale, meaning someone like this guy can get a rifle with limited mag capacity, restricted to certain types of stocks, accessories etc, but then go out and buy the larger mags and alternate parts to convert it off some guy in a parking lot without the authorities having a clue.