In CS 1.6, it was possible to fire accurate shots with the AWP without actually using the scope to sight; this was called quickscoping. It was done by right clicking (opening the scope) and then immediately left clicking to fire. The result was that the game treated your shot as a scoped in shot even though your scope hadn't actually ever appeared, and thus your shot was precise. (Unscoped shots are very erratic.)
I cannot replicate this behavior in CS:GO and did not play CS:Source heavily enough to know if quickscoping functioned there. Does this still ability still exist in CS:GO?