You may want to aim a bit to the side or above the doorway where the enemies will come out, where the dot is not visible and then swiftly move your aim towards the enemy to surprise them. Your enemies may see this and avoid your shot.
When you're zoomed in, a dot will show on whatever you are aiming at. Sniping can be done by aiming at an entrance and waiting for an enemy to walk into your crosshair. This will be enough to kill any class, including a heavy charged by a medic. A fully-charged headshot will deal 450 damage to the enemy player. This is an effective and easy way, along with no-scoping, to take down some of the high damage classes with 1 shot.
This is enough to kill scouts, pyros, medics, snipers, or spies. If you headshot an enemy as soon as you zoom in, the bullet will deal about 150 dmg. When it is full, you will do the most damage. A meter will charge every second you are zoomed in.
The longer you are zoomed in, the more damage your shots can do.
