- "Command the battlefield with this .50 Cal conversion kit for the RPK. Slow yet powerful with a high-capacity drum mag, this kit is your enemy's nightmare."
- — In-game description
The JAK Cataclysm is a conversion kit for the RPK light machine gun featured in Call of Duty: Modern Warfare III as part of the Aftermarket Parts system. It was added as part of the Season Five update.
The JAK Cataclysm conversion kit alters the RPK to utilize .50 Caliber ammunition and a 15-round drum magazine while prohibiting modifications to the barrel, ammunition, and magazine.