Rolled a Hawksaw last night with hammer forged, full auto, and snapshot/rifled barrel.
Better than vendor?
Yes and No. I actually have this roll, the new vendor, the old vendor, AND one with Hammer Forged, Counter Balance, with Rifled Barrel.
The vendor Hawksaw is a laser, but you will feel the damage fallouff if you try to shoot folks from range. Think about maps like Bannerfall, Memento, Blind Watch, Frontier, etc
The roll you have will be a REALLY tight spread with good range but kick slightly to the left. I personally loved this roll for a long time until I get the really good PDX roll the Gunsmith sold a while ago.
If you can overcome the sway to the left that roll is deadly. If you don't want to deal with that the vendor will be ideal but at the cost of ranged engagements.
Also, consider your playstyle. Can you close the cap quickly? Or do you like to hang back and pepper(my favorite Drizz term btw) folks from a distance.