The Gage Assault Pack Add-on for PAYDAY 2 has 10 achievements.
Kill 200 enemies using the Clarion rifle. Unlocks the "Suppressed Barrel" and "G2 Grip" for the Clarion rifle as well as the "Professor Wrath" mask.
Kill at least four enemies with one GL40 grenade launcher shot. Unlocks the "Sawed-off" Stock for the GL40 grenade launcher and the "Crow Goblin" mask.
Own one of every Gage Assault Pack weapon in the game. Unlocks the "Short Barrel" for the Clarion rifle, "Light Stock" for the Gecko 7.62 rifle, "Plastic Foregrip" and "Assault Kit" for the Gewehr 3 rifle, "Evil" material and "Vicious" pattern.
Kill 25 Bulldozers using the Gewehr 3 Rifle. Unlocks the "Sniper Barrel" for the Clarion rifle, "Sniper Stock", "Sniper Grip" and "Sniper Foregrip" for the Gecko 7.62 rifle, "Precision Stock", "Precision Foregrip", "Precision Grip" and the "DMR Kit" for the Gewehr 3 rifle as well as the "Black Death" mask.
Equip the GL40 grenade launcher, the Locomotive 12G shotgun, and the Improved Combined Tactical Vest. Unlocks the "CQB Foregrip" and "Plastic Stock" for the Gecko 7.62 rifle.
Kill 25 enemies at 40 meters or more using only the GL40 grenade launcher. Unlocks the "Wooden Stock" for the Gecko 7.62 rifle, "Pirate Barrel" for the GL40 grenade launcher, "Bone" material and "Muerte" pattern.
In the Watchdogs job, complete the heist while you and your four man crew are wearing one different Assault Pack mask each on the OVERKILL difficulty or above. Unlocks the "Light Foregrip" for the Gecko 7.62 rifle, "Tactical Foregrip" for the Gewehr 3 rifle, "Long Barrel" for the Clarion rifle, "Void" material and "Death" pattern.
Kill a jumping Cloaker using the GL40 grenade launcher. Unlocks the "Wooden Stock", "Retro Grip" and "Wooden Foregrip" for the Gewehr 3 rifle.
Kill 25 thugs using the Ding Dong breaching tool melee weapon. Unlocks the "Frost" material and "Emperor" pattern.
Kill 10 Cloakers using the Gecko 7.62 rifle. Unlocks the "Skeletal Stock", "Fabulous Stock" and "Fabulous Foregrip" for the Gecko 7.62 rifle as well as the "Volt" mask.