Yep, what is available at PV in the morning probably isn't in the afternoon. Or vise versa.
They have been that way on primers for close to a year. I have always got the primers I wanted within a short period of time. I ordered primers and powder last April, October, and December. I don't believe they showed everything I wanted the first time I looked any of the times I ordered. But a few hours or days later they had it.
I can visualize big semi's unloading at one door while UPS is loading at another door.