Then the reality is quick-scopers aren't your problem.
Pay more attention to how you move around the map and use cover. If you find campers are players in areas that are giving you trouble, just avoid those areas. Keep an eye on the mini-map to see where your team mates are and are dying at - this will give you a rough idea where the action is and where to expect a flank at.
One of the big things I see players doing is chasing enemies. If a enemy runs by and you don't kill him, don't go out into the open to chase. Someone else on your team can likely clean him up if he is wounded. But chasing, you never know if he has a buddy right behind him and so on.
Another thing is reload syndrome - reloading after you kill someone. If you are aiming and taking a moment, you can get 3 kills per clip on most guns, and if you can't kill someone when you have half a clip left, you'll probably die anyhow. So instead, pick and choose where you reload and don't be afraid to use your secondary till you are in a safe spot to reload. For instance, in large fire fights, generally around Domination points, I'll eventually empty the clip on my FAD or MP7, then I switch to my MP9 and stick with it till I can get back a bit and the action is over. Why stay on the MP9? It has a faster reload than an AR or SMG and I don't lose time switching back and reloading the primary. On classes without Slight of Hand Pro, I generally use handguns for the secondary, just because of the swap time - which lets me finish off someone if we both end up with empty clips often.
Anyhow, what I am trying to say is some small adjustments in play can make a huge difference.
, I always use Specialist or Support.
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