The genie is long out of the bottle on firearms, and there's no getting it back in. You could close down all industries related to guns, confiscate and melt down all firearms in the world, burn every book mentioning them, and outlaw all aspects of the knowledge, yet there will be people who remember, or who will rediscover the concept.
If they are ambitious they will gain power through this knowledge. If they are ruthless they can gain a lot of power with it. If they are smart and lucky they can subjugate the world. Who will oppose them, with our rocks, our pointed sticks, and our harsh language? Have we so easily forgotten the errors made after World War I that made World War II inevitable?
Remember too, that though you may depend on law enforcement for protection, they can only offer deterrence; they cannot protect you from the murderer in front of you, for once he pushes past the deterrence that the threat of justice offers, unless there's an officer right there, you're on your own. You may never encounter such a problem in your lifetime, and even if you thought you might, you may still never want to own and use a gun. Such is your right to choose, but so too is the right of another to chose not to accept that limitation.
Crime is a problem, guns are just one of the tools used by criminals, as are cars, cellphones, knives, piano wire, cement, baseball bats, computers, etc. Take away guns, you still have crime. Address the problem, not the tool.