When you use a sniper rifle like it should be used and actually aim using the sights. Seen to be inferior to its counter-part Quick Scoping as the shot isn't determined by luck or a glitch in the game.
Also the only real method of sniping in reality.
CoD Addict: D00d! WTF!? Hard scoping n00b!
Hard Scoper: The sights are there for a reason, why don't you try quickscoping in real life.