That's a great weapon, and really good for killing thugs (kind of wasted on anything less). You don't actually need DLC to get one, you can build one quite early in the game from stuff that's lying around.
The key is to keep picking up everything, and repairing and upgrading your weapons as often as possible. Oh yeah, and keep topping up your health, it makes a huge difference in fights.
EDITED: 8 Apr 2015 15:33 by DSMITHHFX