Singularity

Actually, this achievement is relatively simple to pull off once you learn the trick: the tick creatures (the ones that explode when they get close to you) can be killed with one very short burst of fire from the Autocannon. Kill a lot of them in one go and you've got this achievement in the bag.

Once you find somewhere were quite a few of them come out (the neck of Lenin's head on The Pearl, for instance) you can rack up at least 9 kills in one go without expending much ammo. Then just let off a few sharp, short bursts at a few more random enemies (aim for the head to keep ammo use down) and you should score it in no time.

I managed this with ONE upgrade to both clip size and damage just incase, hehe.

Easiest way for me was in the last level after the TMD gets the Uber upgrade. There will be groups of enemies as you make your way to the final room. Simply upgrade Deadlock(DL) all the way and when you run into a group of soldiers, throw it down and let them run into the DL walls. From there all you have to do is walk right next to the individual soldiers and shoot about 3-5 bullets into their faces. Then drop the DL and watch the bodies fall. Just rinse and repeat as you make your way through the corridors.

The level near the end of the game where you have to descend into the reactor to "cook" the bomb is a good place to get this one.

Before starting this level, make sure you've purchased the damage increase and clip size modifications for the auto cannon; preferably both (six weapon tech kits in total).

Then, make sure the gun is fully loaded with ammo so you won't have to reload it.

Throughout this level are numerous blue ice barrels. Whenever you see one, pick it up by clicking the right analog stick and when you spot an enemy soldier, throw the barrel at him. When the barrel blows up it will freeze the enemy (or enemies if more than one guy is around), at which point you can then shatter them with two or three bullets from the auto cannon.

Do this every chance you get, and the achievement will unlock before the end of the level.

*Worded to be spoiler free.*

This is the earliest possible way to get the achievement, and it does not require any upgrades.

Very soon after you get the Autocannon, you will face a courtyard full of enemies from up on a walkway. Clear the courtyard, drop down and move through another small room. Then you will kill two more enemies and one heavy enemy. Once the heavy is dead, you will be chasing something plot-related and this is where you begin your achievement run. Reload the gun, then just keep moving forward and make sure you aim for the top of their bodies, preferably a head shot and only fire in short bursts (3 shots). You will pass 2 checkpoints on the way, so be careful because you can't restart from the beginning, but there are more than 15 enemies during this sequence.

Interference22 is right, the ticks near Lenin's head early in the Central Docks level offer a great place to start a run. But if you're like me you instinctively used Impulse on the ticks and went past this area.

So I got this achievement on The Pearl itself, before getting below deck. After you climb the ramp to board the ship, you'll encounter small groups of Zeks and soldiers around shipping containers. Liberal use of Deadlock (preferably upgraded) makes this achievement a cinch here. For each small grouping of enemies, throw down your sphere and plug your stationary targets directly in the head with the Autocannon.

(Although using is one way to switch from TMD to right-hand weapon, doing this will make you reload. To avoid this, after laying down the deadlock, either pull or double-tap to re-equip the Autocannon.)


Upgrades, bullets and bullshit, oh my!

The Autocannon is unrealistically weak, at least on Hard difficulty. Two solutions on this page say 3 bullets is enough; I say that is bullshit. I specifically noted instances when these non-armored enemies survived 3 bullets to the head, and that was with both damage upgrades applied.

The Autocannon need not be fully upgraded to both clips (two really is overkill for this achievement), but I highly recommend one clip-size upgrade and at least one damage upgrade, preferably two. Then when doing your run, make sure to put at least FOUR BULLETS into each enemy's head. I was plugging them with 4-5 bullets each, and had not begun to deplete the third row of ammo when the achievement popped.

Happy plugging!