I have a Bushmaster M4 in 6.8. - "significantly reduced magazine capacity" - no. Going from 30 rounds to 26 is hardly significantly reduced, especially when you consider what you're getting for that 13% capacity loss.
If you shoot someone, and the round is not heavy enough to put them down...you need a bigger bullet.
The 5.56 was the old NATO bullet, supposed to create ease of ammo if the Russians came. We’re not in a NATO world anymore, and we’re not fighting Russians.
Was watching Futureweapons the other day, and they were showing a new PDW, shoots the 6.8 caseless round, short barrel, weighs the same as the M-4, highly accurate, much better put-down. If this is out there, why are we wasting time?