I think the Concussion Rifle should be deemed the most awkward weapon in Halo.
If you're in a vehicle, it sends you flying, but it hardly ever does enough damage to kill you. It just does enough to literally concuss you, where teammates can finish you off once vehicle-less. It takes 2 direct bursts to kill, but normally takes 4, 5, or even the whole clip depending on where you're firing from and if there are nearby walls to ricochet the damage.
I hope that in Halo 4, it has more damaging bursts instead of acting like a divided-by-zero bubble-gun.
Awkward.