I have bad dps need help

I don't raid but have begun doing some Heroics and am new to being a Hunter, I believe I have decent gear... but I still do fairly low DPS.

My rotation is usually by priority:
- Rapid Fire
- Serpent Sting
- Black Arrow
- Explosive Shot
- Cobra Shot/Steady Shot (depending how low my serpent sting is to refresh)

Any ideas or tips on what I am doing wrong? Cheers.
Awesome guild name.

http://elitistjerks.com/f74/t110723-cataclysm_survival_hunter/

Go read.
what he said ^


also reforge your mastery to haste and hit(for raid bosses if your raiding)

mastery isnt a great stat for survive atm.