How do I defeat Atlas?

So, I am currently up against Atlas, but I can't beat him.

I am enacting my 1-step battle plan (shoot at Atlas a lot), but it doesn't seem to be working. In addition, while I am doing this, he's tearing me to shreds because I can't seem to dodge his projectiles at all, even while sprinting!

• Am I maybe supposed to shoot something else in the environment, and not the giant boss itself?
• Am I simply not shooting him enough?

Some tactics would be appreciated. If it helps at all, I have the N.R.G. Railgun at my disposal, with which I've been shooting his giant glowing noggin repeatedly — to little apparent effect.

I thought I had to shoot at his head to but I soon found out that you have to aim at the parts of his body that glow orange. You have to defeat his orange armour twice and on the third time he goes berserk and rips out some sort of red gear and totally demolishes you no matter what. Im still trying find out how to beat him completely.

Hope this helped :)

In the official game forums, a user has posted a video on YouTube on how to kill Atlas on insane. He also added some comments for the various phases. Hope this helps :)