I don't know what it is but the Halo 4 BR seems extremely sloppy to me, more so than the Halo 3 BR which was notorious for its spread. Maybe its the oversized reticule, Halo 3's reticule was a lot smaller and it was clearer when it was on the head.
I just feel like, especially when strafing, the bullets go anywhere.
BKtitis, check a doctor