It's not a Barrett. In fact, it's not even based on the Barrett, or will look anything like it. It's based on the SR-93. Once again, I'll say that the only reference to the Barrett was made when the devs said they used it for sound production and that it said "It sounded like God coughing, because it was just so loud".
Honestly, if you, you have two choices. SMG, or a Short rifle. If you plan on rushing, go with an SMG unless you plan on being able to use the faster firing short rifle, but then you better be able to make those shots count. If you prefer a slower playstyle, you probably shouldn't be using a light in the first place. Lights are meant to move fast (which is their main advantage, so not using that is detrimental).
1. I was commenting one what that person said. I never said which light rilfe I was personally going to use.
2. Your rushing idea isn't great since lights have low health and would be shot down pretty fast (reference to the orange)
3. My personal preference is the light rifle because of it's semi auto and accuracy so making shots count won't be hard (reference to red)
4. Ever heard of hit and run? I could run around, pop a few accurate shots and keep running. Also, I can use whatever body size I want. Just because i'm light doesn't mean I have to constantly move. Maybe I just like how high they can jump in one leap.....(reference to green)