I'm starting to hear that the problem is traditional gun owners, motovated by a shortage panic, are stockpiling. That the situation is getting serious enough that it will soon effect the war on terror (or whatever is the new PC word for the ongoing conflict).
Now I imagine every issue that has been brought up is part of the issue, but what I find interesting about blaming "traditional gun owners" is it is partially true, you get a news (propaganda) story that blames gun owners, makes them look unpatriotic, and you don't have to acknowledge the political issues that may have begun the motovation of the shortage panic.
So I want to sum up the "buzz" reasons for the ammunition shortages, let me know if I missed one. BTW, I looked back, and there has been a building concern for ammunition shortages since late 2006. I have only had serious problems finding ammunition since 12/2008, or so (and thats .357 Sig).
We have heard there are ammunition shortages due to increased military demand (effecting supply of all calibers due to production capabilities and availability of resources).
I have also read that part of the issue is the increase in SWAT and other paramilitary police teams since 2001.
I have also heard it is the economy. It is all tied together, and while there is demand for ammunition there are other issue along the chain (global weaking of fiat currency, changes in shipping, problems aquiring the raw materials used to make brass, bullets, powder, etc).
The economy / politics is also blamed because uncertainty makes people prepare / stockpile.
Next, all the new gun owners. In the panic (due to the economy and due to fear of who is in power in DC). With those new guns, they purchase ammunition.
I've also read (and must admit wonder) about conspiracy like issues. Manufacturers gearing up to make serialized ammunition to "environmentally responsible" ammunition due to future legislation.
Looking back, almost everything I've read, I don't have any information from a real source. Everything comes from a wire service, and often you never really know who is being quoted. The only fact I know is ammunition is getting harder to find.