The The Butcher's AK/CAR Mod Pack Add-on for PAYDAY 2 has 8 achievements.
In the Nightclub job, have 12 hostages or more on the dance floor when you escape. Unlocks the "Aluminum Grip" for the AK weapon family, the "Aluminum Foregrip" for the Krinkov submachine gun and the "LW Upper Receiver" for the CAR weapon family.