Actually I was implying no criticism of the M16 at all by '50 year old rifle design'. A lot of people rate the 1911 Colt .45 as the worlds best pistol. And it's a century old. People are certainly still winning competitions with it.
You could hand a modern rifle to a 1916 doughboy and he'd be able to use it with a little examination. Firearms development seems to have reached a peak for the moment.
I'm as sceptical as you are of anything someone needing funding says. But thought it was worth mentioning if you were thinking of equipping yourself.
I'd feel stupid if I'd done the modern equivalent of buying a load of muzzle loaders in 1861 to find the North was massacring the Confederacy with repeaters a few years later.
By the way; they are following two lines of research; caseless and polymer-cased as I said in my first post. So your thoughts on replacing brass with plastic are being pursued. Mechanically it could be identical to an M16; but made of something that didn't need brass to eject a lot of heat along with the casing. Or maybe they'll come up with a plastic that's as good a heat sink. Apologies if this is nonsense. I'm no engineer.

The Sock