I think this is all getting rather far away from the core of the considerations about gun control. People don't really care about suicide as gun violence, generally, because of an important and often disregarded part of risk management: people have a preference for risks that are on "their terms."
People intuitively prefer driving to riding in a plane, smoking to "wifi radiation," and state violence to terrorism, because in each case, the preferred form of risk is one that, at least naively, the person in question can control. If you die in a plane crash, you're just doomed. If you die in a car crash, you probably went out fighting to the very end -- or at least we prefer to believe. Likewise, you can quit smoking whenever you like, but trivial (or imaginary) radiation sources around you are insidious. A generic, imagined terrorist might target anyone, but the police only target criminals, at least in theory.
This is why we allow cars to be such unsafe deathtraps while fearing airplanes. It's why TSA security theater is so popular.
This isn't to say that people are wrong to want to control guns (I for one want to see guns restricted to well-regulated militias, as the second amendment clearly states). But it is why arguments regarding actual deaths is less effective than arguments regarding powerlessness. Ultimately, people would rather have a poor chance of winning a rigged fight than they would have a good chance of avoiding some instant death. So look for a way to argue that gun control is a way of taking back power and you'll get a strong argument. I think that the March For Our Lives has it right: "We want this policy, and unresponsive politicians have taken the power to make that policy away from us."
*Did you read that it's beginning to look like Alzheimers is going to be treatable? I'm quite hopeful, myself.