It is well known that many of the violent crimes in the U.S. are committed with firearms. Less adequately documented is the frequency with which victims use guns in self-defense. We used National Crime Victims Information survey data to examine incidents where victims employed guns against offenders. Between 1987 and 1990 there were an estimated 258,459 incidents of firearm defense. An annual mean of 64,615.
Victims used firearms in 0.18% of all crimes recorded by the survey and in 0.83% of violent offenses.
Our conclusion? Firearm self- defense is very rare compared to gun crimes.

• http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=retrieve&db=pubmed