Lag Problems??

Hello. I'm having trouble with Black Ops... I have tried both wired/wireless connections. I hvae 3/4 bars. and I'm not lag moving, or having screen lag, and I live in US with great internet connection... Everything sounds right doesn't it? Well, the problem is that whenever I try to kill someone, it will take more than half the clip to their body. I tested it out, someone was afk, I walked up to him and shot a clip and didn't kill him. Anyone else that has had this problem and a possible solution?

Thanks