really, I was using sawed off earlier, rolled up on two enemies, they were clipping inside each other, blasted them and they both only lost about 25% hp. This happened a few times, until my aimer was right up in the middle of their chest it was having issues killing mobs it would kill before.
It could just be my imagination, who knows.
Random possibility: might it have stopped critting so frequently? I recall my courier critted a lot.
They may of nerfed it and not adjusted the stats on the item description by mistake.