The lesson is twofold, really. Firearms facilitate killing at a distance, giving the user a feeling that he does not risk personal injury when attacking another. More than prison sentences a major deterrent against violence is the fear in the perpetrator's mind that he will be injured while attacking another. This is true. However I don't think you can rationally argue against the statement that guns facilitate killing people .
Guns make killing much, much easier.
I since sold the revolver. A pellet rifle and a pellet pistol. I use them for target practice. None of these weapons allows the sort of impersonal, long-distance killing that a gun permits. This, along with my trusty Kubotan , is the full extent of my personal armory.