If u search the boards, you may be able to find a good kit to use. But honestly, its all luck based. The closest I've gotten was 19 and that was on Standoff with the MK48 LMG. The main way to obtain it with more ease is to get on a game full of bad players, but again that's all luck dependant.
My friend got it on Slums Kill Confirmed. We rolled in a 3 man party and he got it because I ran support and called in 4 VSATS, he got 4 VSATS and the other guy 2 VSATS and a Lodestar.
What's funny is he was using the SVU and wanted to kill himself to get more ammo because he was going for Blood Thirsty. The our team didn't rage and no one on our team was collecting tags or anything.
There is no pleasure in life. There is only a relief of pain. We have to suffer to be on top.