It's an interesting question whether or not this should even be part of the gun control debate. IF, if, you accept the idea of a "right to die" (I do, FWIW), then people who voluntarily choose to end their lives using a firearm should not be counted as "gun deaths" in anything like the same way as homicides, or even accidental deaths.
Now granted, that's a controversial topic in it's own right, but it's something to consider. If somebody choose to die, does it really matter how they do it?
Of course, it also raises the issue of whether or not people who (try to) commit suicide really want to die or not, or are just "looking for help" or whatever the phrase is. I don't really have a stand on that.