Could also be that hunting season is coming up and Mfg's are preparing by producing ammo instead of producing brass for hand loaders. As for rimfire, retailers responded to excess demand and hoarding by raising prices until ammo stayed on the shelf for more than a few seconds. There was never any "shortage", but simply excessive demand, and the market responded as it could under free market rules.

Then there's the Corporate raiders who respond to a big up tic in demand by buying out other companies and taking the profits until demand falls again, then strip the company of all its value and sell off the shell. A great example of how the Free Enterprise model doesn't work, or shouldn't work. Remember the Junk bond market in the 80's? Or the home mortgage market of the mid 2000's?