Contents of an interesting lecture I attended several months back.

[stanc]

:???? In what universe is the 6.8 spc a suitable replacement for 7.62 DMRs?

Freed from the M16 mag length restriction, 6.8 SPC can be given a streamlined, long-ogive bullet that would provide external ballistics as good or better than 7.62mm.

How exactly is the 6.8 spc a better candidate for an LMG than the Grendel, other than your unfounded assumption that they'll be a problem with developing links?

As I said before, it is not an unfounded assumption. It's proven fact that:

1. The M27 link can be -- and has been -- adapted to 6.8 SPC, but not to 6.5 Grendel.
2. The M27 link is not compatible with 6.5 Grendel case head-to-shoulder dimension.
3. Belt-fed 6.8 SPC machine guns exist, but (AFAIK) belt-fed 6.5 Grendel machine guns do not.

In my book, a working machine gun that fires an inferior cartridge is far better than an imaginary machine gun that cannot fire a superior round.