1. Criminal on criminal
3. Accidents ~ frequently with older, or worn firearms, and
4. Mentally ill shooters.
There's probably little to be done with the criminal on criminal stuff simply because the Democrats don't want to offend their families and lose those votes they need. it's pretty much the same problem with suicides. At the same time the best way to deal with accidental use of firearms is simply to collect old, nasty guns and replace them with new, working guns. Republicans will reject the idea of taking in the old guns, and Democrats will reject the idea of arranging for their replacement with new guns.
Then, there are the crazy people ~ again, the Democrats fear the loss of voters.
But those large state institutions might be useful ~ start rounding up Democrats, put them in the institution, give them drugs and electroshock therapy, and barrage them with NRA movies 24/7 ~
Getting the Democrat thought patterns out of the picture will make it possible for the rest of us to resolve the problems.
Uh, you're going to have to provide a multitude of examples.
I know of any number of antique firearms that shoot just fine.
Now there you go - they do prove their dangerous lunacy on a daily basis. Good idea!