https://youtu.be/DoJnEcQMt7M

Prefire 

https://youtu.be/-8Fm5myyR0Q

0:30 - He didnt saw or heard me but he wait for me.

https://youtu.be/rWczlSKpsJk

Subscribes are in russia but people say he hack, 1 shot kill. 

0:51 - it was 80hp, 1shot = 0 hp.

1:05 - triple 1shot kill, it was 100hp, 1shot = 0hp.

http://battlelog.battlefield.com/bf4/ru/user/I_Rus_Voron_I/
https://youtu.be/rWczlSKpsJk?t=31s
1shot kill, wallhack.