Bloodmeat by Protest the Hero.

I've been trying a while to challenge myself and figure out keys by ear. I've been doing fine with some simpler songs, so I moved up and tried to figure out this key. And even looking at tabs it just looks all over the place.

Are they changing keys throughout the song quite often?
yes... its full of changes, but a general rule for metalcore is....put the word MINOR after the name of the lowest string and 99% of the time youv got the tonal centre