> What historical precedent is there for infringement of Constitutionally-enumerated rights of others based on suicides?

There is no requirement that a precedent exist for limiting personal freedoms for the sake of safety. We infringe personal rights in the name of public safety all the time, not the least of which is current, existing gun regulations, all the way down to far more benign shit like speed limits, and not letting people scream "fire" in a theater. The 2nd Amendment was itself a modification to the constitution, ratified some time after the constitution itself. Hence the "amendment" part.

And as numerous gun activists have pointed out before me: The individual ownership interpretation goes only back to the 2008 ruling in District of Columbia v. Heller, and is not itself law, merely judicial precedent. The right for every single American to own a gun is not enshrined in any law, merely an interpretation of a law, and the law itself was written in an era of single‑shot, muzzle‑loading firearms, not modern semiautomatic rifles, and further, it was written to promote the creation of, and I quote, "well-regulated Militas," not "Ted up the street who owns the gas station."

Further, even if it was spelled out, in the 2nd Amendment, in clear words, that every single American had the innate right to buy and use an AR15, that does not make it unimpeachable or forever carved in stone: We can change that. We can amend the amendment, hell, we could reverse it entirely. The problem of gun violence is a hard nut to crack, and the culture of American gun ownership is long standing and on the whole I myself quite like guns. That said, I think they're far too easy to get right now, and I am far from alone in that opinion.