- Campaign level 8, "Project Nova".
I just unlocked this achievement, and it was MUCH easier than I thought it would be! What a relief that was. It was way harder to actually plant the bomb in this level. So do not worry about getting this achievement, if you made it this far on Veteran difficulty, it will be peanuts!
IMPORTANT: Have TWO guns with fully loaded magazines ready!
Basically, when you have planted the bomb, you need to make a path. At the left side of the bomb there is a huge pipe. Wait for it to blink yellow as a sign of interaction, and shoot it. Run upstairs and exit the chamber.
When you are about to exit the chamber two guards are waiting for you outside, but you can see them as their guns show around the corner. Quickly shoot them with as less bullets as possible (just a burst) to preserve your bullets.
Yes -- this is Veteran difficulty. But you can actually do this: KEEP RUNNING AND STAY TO THE RIGHT SIDE OF THE SHIP THE WHOLE TIME!
Ignore the enemies that are above you! For some reason, they will be more busy trying to get a good shooting position than actually shooting at you.
Read the comments to this solution to see how easy this was for other people as well!
Use bursts to take enemies down that cross your path, and when your gun is empty, DO NOT RELOAD. Instead, switch to your second gun and CONTINUE the sprint.
If you don't make it, pull out and hold a hand grenade to commit suicide and you can try it again. You will spawn back to the point right after you shot the huge pipe.
Good luck soldier!
If you have any questions, please don't hesitate to ask!