Dead Effect 2

Mission 6

If your weapons are full shoot off a few rounds and reload to pick up ammo box

1. As you start look to your right.
2. As you start behind mech to your left.
3. As you come out of the water and towards the first door look left.
4. To the right of the first terminal you hack.
5. As you go through the door it is straight ahead of you.
6. To the left where you go back in the water.
7. Now do a 180 and you will see a locker, secondary ammo inside.
8. When in the water your objective is to go left instead look right
9 As you come out of water again look right.
10. After going through the door straight ahead.
11. In the locker down the corridor.
12. You are now in the boss room just search the walls on the outside and the center room. Do this after killing the boss and before using the terminal. Do a couple of laps to play safe

The Above guide by FPSDeath is accurate to where the placing of the ammo boxes are, but the secondaries ones dont appear for instance if you have a melee weapon on, he also forgot to mention that grenade ammo boxes count as well, and I tried for the longest time to get the achievement using that guide but it turns out you also need to pick up all ammo boxes dropped by the enemy, so make sure you look out for those !