I came to the same conclusion today while trying to find a few bricks of my favorite caliber. I can't find it now, but a recent article said that since there are twice as many 22's as all other calibers combined, they account for the majority of shootings. While the article was obviously discussing gun control, the pertinent point is the sheer preponderance of 22lr firearms in the hands of general society. I've always just bought a 500 round brick when I need it for more practice (around 100 left) but never stocked up. This shortage for a simple scare has also proved to me the importance of stocking up on that basic caliber. With the popularity of the round, in a true emergency, 22 ammunition would have great widespread appeal with regard to bartering/currency value. Obviously, such value would be in addition to its true utility.