Syndicate

The first guide basically has it down, I just want to put this out there for the people who just want to boost it any way. As it says above, the first level of coop, private match, normal, by yourself is a great level to boost it on. I got 120 penetration kills on ONE run through. I killed EVERYONE that I could through the wall except the first liquid armor and some jerk-off shotgunners who run up to you. You either kill them there or try to run behind a cover before they run up and shoot them through it. For this achievement they do not need to be hiding or "in cover" you just need to shoot through something to kill them.

Heres a runthrough of what I did. Starting wep is sniper, with C2C pulse (I had mine maxed out which on normal means pseudo invincibility) and the second wep/app doesn't matter, I ran virus(unless you're death prone then run c2c and reboot) and try to have some chips in DART overlay areas and health.


When the mission starts run up the stairs to the right and have the two guys get "seen" by your character. Run back and throw up dart, shoot them through the stairs area. Run back up and snipe the first runners through the little cover infront of you. There is a sniper on the wall in the distance, line him up with the pole and shoot him. Run down and activate the barriers and stay behind them the hole time. Shoot all the rushing guys with the sniper, and if you need the ammo the building that is 2 feet next to you has the ammo case. When everyone is gone (no more rushing at you) walk up to the turret and breach it. Climb the stairs to the left of the APV and breach the huge doors. "Mark" the guys infront of you, duck, then shoot them through your cover again. Once they are done run into the next area, ammo up, and breach the door. STAY IN THE AREA WITH THE AMMO CRATES! This way the people are all infront of you and spawn the most before the liquid comes down. Go around the corner, "mark", run back, and snipe all of them. Keep this up until the only one left is the liquid. Breach the liquid (I believe this counts since as soon as he is on his knees thats "dead") and run behind the wall and go for headshots for most damage. Run behind the wall after a chiprip (or let him die) and the next area door will open with some guys behind it. Pop them all in dart behind something.

The next area is the area where you drop down through the skylights. Stay up top and kill everyone you can through the roof. Once ready jump down and either hide from the turret and kill or disable the turret and run around freely. I am not sure if the glass counts as cover but I didn't use it to shoot through any way. Again, finish the room off where they no longer spawn and proceed. Turn the corner outside and spot the few targets infront of you (two on top of the building, one halfway down on a small roof, and 2-3 on ground level. Kill them all through cover. Run into the hanger area and don't leave the door until they stop spawning. Make sure not to close the hanger, that way if there are any spawn straglers you can kill them. Turn around, look up and mark the guys above you, then go back into the room and pop them. Run to the last area.

Time for the boss. Just stay back and kill everyone infront of you that you can. Go out enough to spot both guys on the wall to your left (in each corner) and kill them through the room wall or anything you want to use. Now the boss could send some minions at you which results in more kills but only sent 2 waves at me. Keep shooting the Colonel through the wall after breaching until he dies. Level one complete and around 120 kills closer to this chievo. If you got any in compaign it will make the boosting shorter. Good luck and leave questions in the comments.

The ACR-10's scope, the sniper rifle, and the Coil Laser Rifle's secondary fire (the single shot burst that uses 50 ammo) can fire through walls in the single player. The same weapons can fire through walls in the multiplayer once you get the upgrade that allows it (MPB Munitions for the first two and Disposable Liquid Coolant and Helium Focus for the laser coil).

Really, just do this as often as possible, while playing through campaign and while going for 100% in multiplayer. It's a good idea to grab the chip upgrades for extra DART duration and damage to make this easier in both campaign and multiplayer.

Do be aware that some surfaces can't be shot through, usually level boundaries (shooting an enemy on the opposite side of an area you can't travel through) and some crates and walkways.

Edit: Just wanted to add a few things. Since you'll probably want to save this one for after getting other achievements (no sense wasting cover piercing kills and time by going for this first), you'll have a maxed out agent that will have no problem with normal. That in mind, go for damage link and battery apps, both will refill DART when activated if fully upgraded (and will likely reduce most kills to 1 shot instead of possibly 2).

Made a video to best level to grind out for this achievement. Because of the online servers are officially shutdown!