Sadly no.
If you're talking about the museum level from Modern Warfare 2, then probably not. That was a one time thing.
No.
the single player modern warfare is a campaign story, and the multiplayer has different game modes where you compete against other players and level up, but theres no story.
There isn't one in there.
Errr... By killing people and getting experience points?
10 prestige level 70 commander
In Call of Duty 4: Modern Warfare, the M14 rifle is unlocked at Level 46 in multiplayer.
Just play the game. It is unlocked at a very low level in multiplayer. It shouldn't take long to unlock it. Maybe 1-3 games.The Walther P99 handgun is unlocked at Level 10 in the Multiplayer mode of Call of Duty: Modern Warfare 3. In Survival mode, it is unlocked at Level 42 and costs $250.
This is quite a vague question, but if, by chance, you are asking at which level the G3 unlocks in Call of Duty 4: Modern Warfare's multiplayer, the answer is at level 25.
In the mission The Hornet's Nest, there is a hidden Thumper in the ice cream shop. Or do you mean multiplayer? You can get it at level 14.
Yeah there is! I know there is for the PC but i am not to sure for the PS3 olr XBOX. Have a look on the net!
Nothing. Even on veteran. It's pointless.