I don't get it.

In our hardcore server I can stand next to a camper and unload 2 full clips into their head with no kill and they casually turn round and snipe/pistol me... and no, there's nothing wrong with my aim.

I question this part.  

Ive had that happen to me a few times.  I will have the ballistic gear on, which I would assume would make me alittle more bullet resistant, get the drop on someone, dump a full clip in to their head and body yet they manage to kill me with just a few rounds.

After trying a few things, its obvious it's a latency issue. Specifically the total (or near) lack of proper predictions. This is a low ping winner game for sure.

How can you tell what you ping is.  I looked in the Tab display and didnt see anything.

I've noticed at semi-close range I am better off just firing from the hip to get a kill.

its not hardcore no setting for it.

still takes 5 or 6 shots to kill in ether server

I don't know but it seems to me that when I am having the same problems as you guys (can't get the kill ) the other team is beating my team by a large margine ( 28/75). When it's a close game I don't have the problem.

You can get a rough ping via server browser, or do it manually.

As for 5 or 6 shots, that's not what I am talking about. I mean full clips, reload another half a clip over about 5 seconds and they are still +60 health.