Does the 6.5 grendel have the potential to replace the 5.56 for the military?

[LRRPF52]

Yes it does. But, the squad automatic weapon and the individual weapon have always been the same caliber. It's a safe bet that if a 6.5mm CTA LMG is fielded, a carbine that fires the same ammo will also be adopted.

So, in the event that cased-telescoped technology does not pan out, I just don't see a Grendel LMG entering service without the carbine also being 6.5 G, despite the drawbacks you've noted.

Many units have been using the Mk.48 7.62 NATO LMG in place of the SAW, which is obviously a different caliber than everyone else's M4's.