Vito0842,609,719 Locked 22 May 2014 24 Jul 2014
This is where you can find the Assault Rifle Upgrade.
Assault Rifle Upgrade – At the start of chapter 12 you will be dropped near a broken train cars. Climb the ladder and enter the train car. On the first floor you will find the rocket launcher upgrade.
I found a good spot to get five kills in ten seconds was chapter 11 when you are on the U-BOAT. Just kill the first two Germans on the lower level, then change to duel-wielded assault rifles, only one needs the rocket attached. And run to the top floor and there will be five or six Germans on that floor. Just go to town on them you may have to run into the next room, as they might not all run at you. It may take a few attempts to get five kills in ten seconds. Hope this helps