O'Reilly fan and lifetime hunter here.
Seeing someone buy a crapload of ammo is two things: prevalent and usually nothing.
What I mean is that I bought a thousand rounds 10 years ago because it was cheap. I still have half left, btw.
And so many people buy in bulk that it would completely bog down any law enforcement agency if they tried to dtermine intent any time someone bought ______ rounds in 1 purchase.