The majority of folks that have guns will use them as ornaments, and never have to actually use them. A significant minority, it seems, will actually behave more violently at some point, than they might have without easy access to this efficient killing machine.
The inclination to violence is a part of human nature. And of course it's an inclination that will be stronger in some of us more-so than in others. So when we increase the number of guns among any population of humans,
and we increase the number of humans in possession of them, it will naturally result in there being more guns in the hands of those humans who are more violently inclined, within the general population. And they will then use those guns when they become violent.
A handgun is a very simple and effective machine for killing other human beings. So when we put these very simple and effective killing machines in the hands of people who are inclined toward violent behavior, we make THEM
more effective killers. And this is why increasing the number of hand guns in a population, and especially increasing the number of people with hand guns in that population, will naturally result in an increase in violent gun deaths in that same population.