I would imagine the main reason for changing the case design is to keep from having to pay any type of royalties on using the traditional .308 nato round and just isntalling a flat tip bullet into it. Now that is just my own opinion there, so correct me if I might be wrong. And while they are at it, probably taking the opportunity to streamline the cartridge to cycle better in a lever styeled gun. I am excited for it, finally a true long range levergun. I love the feel of a good lever action rifle, they just work right for me.