Interesting and somewhat relevant link here: http://www.accuratereloading.com/223sb.html
Ok, that's just what I need in a combat weapon- a big clamp and worktable to clamp it to. I say that playfully, but that's the whole point. These guys are in combat- not a turkey shooting contest. Their weapons have to serve them in a wide variety of situations. YOu can't go clamping your personal weapon down to a tripod every time. One reason the 50 is deadly out to 1800+ meters is because of that tripod and T and E mechanism. But the 50 is a crew served weapon and weighs a ton (figuratively). A tripod for a personal weapon like the M16 makes it useless.