As Robb Allen writes:
Registration is confiscation. No criminal is going to register their guns, and they’re not going to report that they stole them either. I’ve yet to see a proposed law that will target criminals. Well, technically they’ll turn us all into criminals, so there’s that.Actual criminals are hard to catch, but threatening to turn honest people into bogus paperwork "criminals" is easy.
Without some form of registration, a requirement for background checks on private transfers turns into a capriciously and randomly-enforced farce. Indiana apparently had a requirement that all handgun transfers had to go through an FFL from the mid-'80s through the mid-'90s and by all accounts the law was flouted left and right by good guys and bad guys alike; not so when a registration requirement ups the ante of good guys getting caught.
The bad guys? Well, they're going to break the law anyway, so what do they care?