We’ve all seen it: as soon as a new cartridge becomes popular, experimenters start modifying the cartridge case to come up with new variations. These mods usually involve either increasing or decreasing bullet diameter, with perhaps some minor modifications to shoulder angle or case length. One of the most popular cartridges for modification has been the classic .308 Winchester, which, by my count, has spawned five “children” that have gone on to become legitimate factory offerings.