How do you quickscope in modern warfare 2?

If you need the class, it is this.

Intervention FMJ

Any akimbo machine pistols or pistols

Throwing Knife

Stun Grenade

Sleight of hand Pro

Stopping Power Pro

Commando Pro OR Steady Aim Pro

Then all you have to do is get your enemy in the middle of your screen, then hold down the left trigger until the scope has just entered and fire. If you stay in scope for more than one second, it doesn't count as a quick scope. It's relatively simple. Search it on YouTube to find more videos on how it looks like.