Cocaine and other imported hard drugs are easily available nationwide despite total national prohibition and a militaristic level of governmental opposition to importation. Take all the guns away, and demand will find a supply nonetheless.

Or in a country where anyone can make an AK47 in his garage for less than $100 by pressing a shovel into the shape of an AK receiver.

Pretty soon, we'll be entering an area where printable 3D guns are less likely to blow up in one's face, which raises the production costs a little bit in the short term, but which will likely result in even cheaper firearms manufacture.

Oddly enough though, the inverse does exist. If you flood a township with guns, as they did in Kennesaw, Georgia in the early 80s; By passing a law requiring every head of household to own a firearm, they were able to drop crime in all forms by over 80% in the township proper. 25 years later they were able to celebrate 25 years without a single murder in the township, despite population growth of 500%.

Also interestingly, the areas immediately surrounding Kennesaw have the same levels of crime as ever, which illustrates that yes, they didn't solve crime, they only displaced it. On a crime map, there's a ring of 'red', like a corona, around the township proper. It's amazingly curious.