None of the above. Something like the 6mm SAW, but I have some specific cartridge diameter and downrange performance preferences which it may or may not fully meet.
A 6 or 6.5mm for rifle and GPGM, .50 BMG for big stuff, and a SMG & PDW in the same caliber (Maybe like .40 S&W if we could get it to shoot accurately more reliably instead of as flukes!). Simplifies the supply lines, TO&E, and squad organization. No more of this SAW-MINIMI or whatever/M60/FN MAG or whatever mess of TWO different GPGMs being deployed as they are now.
We can beat the performance of the 7.62x51, especially at longer ranges, without being much bigger than the okay 5.56 NATO. That one's great, but we now have one rifle caliber, two MG calibers (one duped w/rifle), one primary PDW caliber, and a FIFTH caliber for the SOCOM pistol.
Have things really improved much since Korea and the "problems" the M14 was supposed to "solve"?????