Has anyone out there used one of these, or got close too one. I just saw one being reviewed on the TV (future weapons) and it really looks the business. M4 layout in 7.62x51 (like the old AR10). The guy left it in a barrel of water, took it out and and will little more than a quick shake fired full auto straight off! Then he did the same with a tray of dry sand after covering the rifle! Plus, while I know the presenter is an ex Navy Seal, for a full mag of 7.62 on full auto, it controlled really well. I have never fired one, but if no one rifle can do it all, this one looks like it has come close.