It is one of the easiest things to sweep snipe.  Sweep sniping guarantees a hit with a sniper rifle.

1. Get a sniper/beam rifle.
2. Zoom in once/twice(make sure the the reticule is red when on the oppenent)
3. Then, start from anywhere near the person, and move the sniper rifle in a SWEEPing motion over any part of the body.
4. It should guarantee a hit.
   

It is very useful and can be done in any sweeping motion.  Headshots are fun to do.

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