One of the recurring camo challenges in Modern Warfare 3 tasks players with getting penetration kills in Multiplayer matches, which is much tougher than it sounds. However, there are some ways to speed up the process that I will cover for you in this guide.
How to Get Operator Penetration Kills in Modern Warfare 3
The best way to get penetration kills is by equipping Armor Piercing Rounds on your weapon in a custom loadout and shooting Operators through flimsy walls. On the Bruen MK9, for example, you can choose the 5.56 Armor Piercing Rounds with no negatives attached. They only increase bullet penetration by a massive amount and even add a bonus to vehicle damage.
