RE: 22 magnum
You can get 22 magnum ammo at both Cabelas, and Bass Pro Shop. My rifle is fond of the 34 grain winchester jhp's, and CCI maxi mags. You'll find the .22 mag to be well over twice as powerful as the .22 lr, and it's still not all that loud. I usually pay about $10 Canadian for a box of 50.
You can't eat what you miss!