Wikipedia has some links to studies collecting statistics on that. Though it's important to note that you're asking the wrong question; if I recall correctly, in something like 90% of defensive gun uses, no shots need to be fired. The threat alone is enough for the criminal to surrender or retreat. What you want to measure is how often a gun use prevents a crime.
Anyway, it seems a middle of the road number from the studies is . . . about a million defensive gun uses per year? Lower bound is 55,000 - 80,000.
Wikipedia also gives a homicide with guns rate: http://en.wikipedia.org/wiki/Gun_violence_in_the_United_Stat..., looks like about 8,000 in 2012. It should be borne in mind that a lot of those homicides are from things like gang violence, and would be conducted with illegal guns or other weapons even if gun laws were super-tight.
http://en.wikipedia.org/wiki/Defensive_gun_use
Anyway, it seems a middle of the road number from the studies is . . . about a million defensive gun uses per year? Lower bound is 55,000 - 80,000.
Wikipedia also gives a homicide with guns rate: http://en.wikipedia.org/wiki/Gun_violence_in_the_United_Stat..., looks like about 8,000 in 2012. It should be borne in mind that a lot of those homicides are from things like gang violence, and would be conducted with illegal guns or other weapons even if gun laws were super-tight.
So I'd say the numbers show a clear win for guns.