Originally Posted by Muppet
You just need to give it time. Once you have unlocked some of the better weapons and there add-ins, it makes a massive difference. Stick with one weapon until you get 100 kills and then you unlock the infrared scope and then you will start to see a big difference in your kill ratio.
Yep the IR has made a world of difference for me...I feel kinda cheap using it though, but I'm not that good anyway.