Gun Control & RKBA

In a moment, all gunpowder stops working worldwide. Artificially generated electricity also stops working, as does steam power and artificially generated nuclear power.

Needless to say, 99% if people are dead within a year.

To your point, though, a few hours after "The Change" occurs, a policeman comes upon a woman being assaulted by a man. He tries to shoot him. *Click* (racks the slide, chambers a new round), *Click* (tries again), *Click*.

He barely manages take the guy out with his nightstick. After discovering that no guns work anywhere, he thinks something to the effect of, "I really never liked guns....but I think I'm really going to miss them."

Most of the the novel (and all of the sequels) are set decades later. People are still having conflicts, but they've had to resort to learning how to use swords, bows, and catapults again.