The big brother to the AK47u, it's the the russian beast, it's an iconic rifle and is widely used across the world to this day, in cod4 it manifests itself as a powerful, reliable, and loud rifle. it's one of the few guns where not adding any attachments is better than adding any, thats how classic of a rifle it is. although in later games this is balanced out with difficulty to control the gun due to high recoil but in cod4 it is quiter controlable and easy to get to grips with, it kicks up a tad when sighted in and all over the place when fired from the hip.
when using the AK47 i'd suggest pre-planning each movement carefully, like all other assault rifles, since they all have a slower aim speed then submachine guns, all assault rifles benefit from planning your shots too