Gold guns

The Golden Guns are a group of guns in Call of Duty 4 that you can obtain by completing all challenges in the corresponding fields:

Gold AK-47: Complete all Assult Rifle Challenges

Gold Dragonuv: Complete all Sniper Rifle Challenges

Gold M1014: Complete all Shotgun Challenges

Gold M60: Complete all LMG Challenges

Gold Mini-Uzi: Complete all SMG Challenges

Gold Desert Eagle: Obtained at Lv. 55

If you Prestige, then ALL of these guns will go with it.