Just got hold of it today and it doesn't seem to be able to cater to the metallica kind of sounds I want. Which pedal should I be looking at to purchase?
I have an OCD v.2 and its an overdrive that wont exactly get you into metal territory on its own. Works great at pushing a distorted amp but on its own wont reach your desired effect. Try a full high gain distortion pedal.
If you are serious about getting good metal tones get an amp know to do metal, ie peavey 6505, Mesa mark III, Mesa recto, etc.
I generally don't like high gain pedals, but the barber dirty bomb will do what you want if you want to stick pedals. The wampler triple wreck is another solid option.