In some states and in some cities, handguns are registered; but in most states, they are not registered to any degree. A registry connects a particular gun --

In some states and in some cities, handguns are registered; but in most states, they are not registered to any degree. A registry connects a particular gun -- a particular serial number -- to a particular person. A NICS check doesn't do that -- it's a criminal background check. Just because you have a NICS check, it doesn't mean you bought any particular gun. You could pass the background check and then decide you don't want the gun after all. You may be referring to a Form 4473 -- the DRoS (Dealer Record of Sale) -- which does record which person received which gun (with serial number) -- and all licensed dealers maintain these records, for all guns they sell (not just handguns). These records form a sort of a search tree, since the manufacturer records which wholesaler the serial number went to the, the wholesaler records the retailer and the retailer records the end user. These records are useful in regulating the traffic in arms; but the decentralized nature of them means that the government can not go on fishing expeditions -- can not just go out and query the database and see what looks interesting today. Here's how the DRoS are used in regulating the arms trade. Say police come across a big box of guns from Colt. They can go to Colt with a suitable warrant and say, hey, where did these go to? And then go to the wholesaler, on down the tree. It turns out this information is often sufficient to localize shady gun dealers who are trying to sell to the mob, the cartels, &c.