There are three kinds of lies: lies, damned lies, and statistics
"you know you are 43x more likely to use that gun against yourself or a loved one than you are on an intruder or in self-defense"
This comes from misreadings/misunderstandings of several studies that have been conducted on firearms and death rates.
Suicide
The suicide figures frequently quoted suffer from a significant amount of selection bias, because they only look at "successful" suicides. If you look at suicide
attempts, things change.
Firearms are
not the most popular way of committing suicide, despite what some people would have you believe. Ten times as many people try to poison themselves or OD. Three times as many people use a blade. What firearms do have that other methods do not is a high success rate.
A study performed by the Harvard School of Public Health found that "The higher rates of suicide among gun owners and their families cannot be explained by higher rates of suicidal behavior". Gun owners are not more likely to
attempt suicide, but they are more likely to
succeed.
Conclusion: Buying a gun will not make you suicidal if you are not already. If you
are suicidal, stay away from firearms.
Homicide
Several of the studies frequently quoted (and re-analyzed in the metastudy mentioned in the
Beast article linked by a previous poster) have major problems with the methodology.
The Kellerman study, for example, counted all instances of firearm homicide, whether they had been committed with the gun kept in the home or not. It turns out that less that 15% of the firearms homicides being counted fit that description, which significantly lowers the risks.
Other studies ignore many potential confounding factors, such as involvement in crime. One study found that 71% of gunshot
victims had been previously arrested and 64% convicted. Another study found that 60% of homicide
victims had drug violations on their record. When you control for factors like these—and I assume you're not involved in the drug trade!—the added risk of owning a gun shrinks even more.
Unfortunately, explaining the problems with the studies doesn't easily fit in a soundbite, so you'll exhaust most people's attention span before you convince them.