Your special weapon is a weapon for special situations, like close quarter or if you run out of primary weapon ammo.
The SVU-AS is the first sniper rifle you unlock in Call of Duty Black Ops 2. It is a semi automatic rifle and can be used fairly aggressively similar to how you might use a slower semi automatic assault rifle. I found it best to be aggressive, but at the same time make sure that I was ready for every engagement I came across as you have a long aim time, especially if you are running, and poor hip fire spread.
Constructors are annoying to face, and Badass Constructors are even worse. They spawn turrets, flying robots and enemies. In addition to that they have a laser that ruins your shields, missiles that kill you quickly and a nuke, which is almost an instant death. But it is possible to beat even a Badass constructor using the right techniques which are outlines in this guide:
If your friends aren’t into shooters or the matchmaking doesn’t work for you, you might have play Borderlands 2 by yourself. The game is designed for coop playing, but as a Siren you will easily get through the entire game without too many deaths. If you preordered the game and have a golden key you will have an even easier time.