Sebastian writes on his 6.8 experience.

More about the 6.8 mm Remington SPC (or 6.8x43mm). Even more.

My buddy Charles that I went on the night hunt with and even one of the guys that ran the night hunt are both into 6.8. I’ve been reading things that suggest 6.8 would make a good replacement for the 5.56x45mm NATO round, because it performs better in short-barrel carbines, has better terminal ballistics, but isn’t quite the load to haul around as the 7.62x51mm NATO rounds — 6.8 is a round somewhere in between attempting to be a purpose-built round that addresses the issues that came along if you trace the evolution of going from 7.62 to 5.56 (from the M14 to the M16, etc.).

Once I get up to speed with reloading, I may have to pick myself up a 6.8 upper and try it out, especially as a hunting round.