Left side of his lower critical zone with a corrosive weapon? I'll have to give it a try next time I'm out there. I've put plenty of shock and non-elemental rounds into and around that crit zone to no real effect, outside of what would be expected.
Every time I try to go where I really wanna be it's already where I am, 'cuz I'm already there
When my friend and I first fought him it was this stupid long war, we had him at about half health after 5 or 6 minutes and he flew over top of me, I started pumping corrosive sniper rounds into his underside and he just died at random.
Just call my name, you'll be okay, your scream is BURNING through my veins http://www.centsports.com/ref/673351