Any grenades or C4
Grenade launcher attachments on AR's
AT4, Thumper, or RPG-7
Kill people with those.
Assault rifle w/ noob tube
One man army
Go play in Ground War, youll probably get it in about 7-8 games if youre decent with the noob tube
Noob tubing from level ground is harder.
Noob tubing from an elevated postion (guarding a flag) is so easy, a 3 year-old can have a 3.0 kdr doing it.