One of the toughest rounds of ammo to find is .22 LR.  Hard to say why there is such a shortage at the moment but people are trading .223, 45 ACP and 9mm for it.  About a week ago, I happened to be on Cabelas site when they posted some Remington .22 LR available.  It's not my favorite .22 ammo but when it's in short supply, you get it.  I ordered 2600 rounds with the thought process that I could trade it for other ammo if I found better.  Yesterday, I found better.  It was Cabelas again but this time it was Federal Champion, four 525 round boxes in a 30 caliber ammo can.  I ordered a total of 6300 rounds.  That will put me just over 10,000 rounds total since I already have about 1300 rounds in stock.  Now, if I could only find .223 in those quantities!