The JAK Burnout Kit is a new Aftermarket Part that was added to Call of Duty: Modern Warfare 3 during the Season 2 Reloaded mid-season update. It can drastically change how the Holger 26 light machine gun works, so here is how to get the JAK Burnout Kit in MW3.
How to Unlock JAK Burnout Kit in MW3
The JAK Burnout Kit Aftermarket Part can be unlocked by getting five Operator or Special Zombie Kills with Throwing Knives. This challenge is only available during Season 2, but the attachment can still be unlocked after the season is over through the Armory.