Its quite easy really. All you have to do is aim at the person you are wanting to kill, wait until the crosshairs turn red, then shoot.
You want to use an automatic sniper so if you miss the first time, you can try multiple times before you are seen. The closer you are to your opponent, the easier and more likely you will kill him.
20 kills with an ACOG scope on your gun
yes
pure luck
The closest you can get to having an unscoped m21 is using an ACOG scope on it.
a hard scope is a scope of more than two seconds long before killing somebody
Line the enemy up in your crosshairs, and pull the scope up and shoot the second your scope zooms in.
u cant
On the XBOX 360, yes.
yes! Its back just like it was in MW2.
Get to middle of screen and luck fire
Walk around with a sniper a just shoot. (Hip fire)
As they are pros or you just lag