"Gun sales are dropping, and NICS checks are being required more and more. There's absolutely no question."
Well, yes...there is a question.
Seldom have we encountered in this forum a series of such cocksure assertions that are not only unsupportable but unconnected to any semblance of economic or statistical data.
Won't even attempt to address all of them [bad use of time], but I'll address the one quoted above, keeping in mind that sheer speculation isn't included in the scientific method.
Gun sales are *not* dropping; they are, perhaps [for a variety of reasons] increasing at a slower rate, but they are certainly not dropping....and NICS/state system checks *are* more common. Do you see the relationship?
If you don't, realize that it is the direct result of more customers buying more new/used firearms from FFLs.
On behalf of those of us who actually have experience in the firearms business, let me suggest you revisit the statistical difference between correlation and causation. We have to regularly or suffer the consequences.
And, while you're at it, why not investigate the BATFE's estimate for the total number of firearms "owned" in the USA. Since it hasn't substantially changed in decades, I'm suspicious. How 'bout you?