Has anyone seen or tried this cartridge? The ballistics are pretty impressive but of course you'd have to have a massive action and lots of powder. It really seems like that would shoot as flat as anything out there. The 300 MK would smoke! Is it legal to use the standard 50 BMG? With the right bullets, the range with one of those seems practically limitless. My information says it propels a 660 grainer at just over 3,000 fps!