in most states someone who has multiple assault violations and a history of mental health problems can walk into a gun show with $700 and 15 minutes later walk out with a semi-automatic AR-15
That's not an assault rifle, first and foremost. Second, selling to someone with multiple assault convictions is itself a Federal felony, and not every gun owner is so careless as to want to take that risk and get pilloried in the press. You're generalizing a worst-case scenario based on a stereotype.
it's not a worst-case scenario, it's a very obvious loophole that should be closed — private gun purchases should require waiting times and background checks
"not technically an assault rifle" doesn't matter in the slightest, no one's impressed by this constant pedantry... yes, yes, it's an ArmaLite 15 and isn't technically an assault rifle because it's only semi-automatic. This changes absolutely nothing, mass shooters are essentially cosplaying during mass shootings with this thing because it looks like an assault rifle and it's easily accessible.
the proliferation of modern small arms is one of the worst things to happen in human history
the facts being "looks like an assault rifle but isn't technically an assault rifle"? that's immaterial to the point, and it's clear you have no desire to engage in a good faith conversation, see ya