The reason .22lr is in short supply is because of your rifle, the 1522, and an endless list of other .22 "black rifles" that simply didn't exist just a few years ago. And now look at the huge number of new .22 centerfire handgun replicas being produced. None of this existed a few years ago. As well, bad economic times drive folks to shooting more rimfire. I shoot more .22 than most folks and I can tell you that cheap bulk ammo was getting more and more difficult to find well before the panic. The panic simply pushed things over the edge or
rim as it were.
Along with the explosion in new .22 guns has come an explosion in rimfire suppressor sales. Supressors, which used to be a rare animal, are now quite common to see at the club. Rimfire gun manufactures are putting out all sorts of guns with threaded barrels that they never had done before.
Gentlemen, this ain't your daddy's 10-22 and Marlin 60 rimfire world anymore. Y'all are dangling 25rd mags from your rifles and blowing through bricks of ammo in a shooting session.... and there is a ton more of ya than ever before.
As far as Midway canceling backorders... don't know. But it has been widely publicized on the Net that Midway was taking backorders on .22 ammo. I can only imagine how many tens of thousands of shooters stampeded to get their orders placed before it became clear there was just no way fulfilling.