Well, I gotta say that bendotcom game every explanation that I've seen in a single thread, but guess what: there's more.
Consider that an average quickscoper has an accuracy of about 50%. If he he hits the first shot he lives, if not, he dies. It takes about 1.2 seconds to re-chamber and fire. It takes about 0.25 seconds to do a quickscope. In total, it takes a total time of 1.45 seconds to fire two shots, and two shots statistically guarantees a kill. In 1.45 seconds, the MTAR-X with the adjusted fire rate (there's weird things with RPM rounding in the game because of 60 frames per second) can shoot 18 times, killing someone at close range 6 times, and at long range 3 times. That means that the MTAR-X user needs to have an accuracy of about 16.7% to statistically guarantee a kill. As you can see, the sniper needs to be 3 times more accurate than an SMG user. If people say that "Pamaj like never misses though" and that my stats aren't accurate on sniper accuracy, that's because Pamaj is the best sniper in the world, and knows that he would be wreaked if he and Crimsix did a 1 v 1.