But what's wanted is a magazine-fed 5,56 SAW, one whose belts are not subject to fouling from sand, nor in those locales where vegetation is more prevalent, where belts constantly foul and snag on the wait-a-minute vines.
It'll be interesting to see if the magazine for a Marine 5.56 SAW like the H&K guns can be adapted to the M16A3/M4 as well. If so, then we'd be in a partity situatuion with the Russians, whose RPK magazines work just dandy in AKs and AKM, and whose RPK74 magazines work in the standard AK74 and AK74SUs. They've only been ahead of us on this for, oh, 45, 50 years or so. Not that the fixed-barrel RPK doesn't suffer some flaws of its own. But a quick-change barrel setup could change that.
Myself, I kind of like these:
