I can't play without bullet trails. It feels like my gun is shooting blanks cause it's just got a look of bad power.
Anyway, do use your scope - that's what makes barrett unique. The thing is, you can see others before they see you. While this is happening, you're crouching/proning on the ground, giving you near perfect accuracy. This makes it easier for you to aim, and if you hit them while they're in "scoped" range, well they don't have a chance against you. It doesn't even matter that you're not using dodging tricks, as they can't see you. When I barrett, I usually move to just short of the middle, pitch up a tent, snipe the first and foremost guy I see and then go into their base (in CTF).
EDIT: Sorry, I failed to see the "law tips" topic, and now that you're OK, I guess this would be for very new barrett users who stumble across this topic.