When it comes to guns or gun control . . . there are no absolute [Catholic] teachings, aside from those concerning acts of violence. Guns can be used to protect human life. They can also be used for sport as long as they do not endanger human life.
Despite media coverage, guns are overwhelmingly used for purposes other than unjust violence. Although we have no exact data on the number of firearms in the U.S., a conservative estimate puts it at about 250 million, not including those owned by law enforcement and government. According to the Centers for Disease Control and Prevention, there were 11,078 homicides resulting from firearms in 2010. The total number of deaths from firearms, including use by law enforcement, suicide and accidents, was 31,672. That means that less than .000127% of privately owned guns resulted in any type of death.
To give some context to these numbers, there are about 250 million registered motor vehicles in the U.S. The CDC reports 33,687 deaths caused by motor vehicles. Guns and cars cause about the same number of deaths. While those deaths are tragic and violent, drivers and gun owners operate more than 99% of cars or guns in ways that do not result in the taking of a human life. Guns, like cars, are instruments that have no intrinsic moral value.
When something is not intrinsically evil, there is room for prudential judgment. In other words, we weigh the positive and negative effects to determine whether or not something is good.