Grendel as a Universal Infantry Cartridge

[stanc]

my guess would be the DOD is stalling cause to be "optimal" they will need a new weapon system as a primary to shoot the 6.5 with a long OAL that would be a bit too long to fit the current mags.

I think they want to wait and see whether or not cased-telescoped ammo technology proves to be viable, before they spend $$$ to field another conventional, brass-cased round and weapons to fire it.

Cartridges like the AMU's .264 USA are nearly as long as the 7.62 NATO round, so they definitely would be incompatible with M4 and M16 variants. That isn't really an issue, though, because historically they have nearly always adopted new rifles when adopting a new cartridge. The only exception which comes to mind is the .58 Rimfire, adopted 150 years ago for use in Civil War muzzleloaders converted to breechloading rifles.

a steel core 6.5 grendel bullet with the same drag / oal as the 140 gr would be "super " from a LMG, like a 6.5 SAW.

Yeah, I'm sure it would.

the current administration is too busy giving away billions to islamics who want to kill americans and spending more billions on tapping our phones to be bothered with little things like better ammo and arms for lowly grunts.

Actually, it has nothing to do with this, or any other, administration. It's the military leadership -- not the President or Congress -- who chooses the calibers and types of small arms to equip our soldiers.