Here is another interesting thought: I had the "Cartridges of the World, 6th Edition" for a million years; it eventually disintegrated. Near the end of book there was a question posed to Frank Barnes (gun guy extraordinaire). He was asked "If you had to choose only one caliber to use all over the world, what would it be?" His response was ". . . a 12-gauge shotgun". This is because of the wide variety loads that can be had or made for it.