Despite the Modern Warfare 2 M4 being one of the few guns you start with in the Call of Duty FPS game it’s actually an incredibly robust choice of weapon, especially if you unlock some other attachments and use Modern Warfare 2 weapon tuning on it. Developer Infinity Ward seems to agree as a rather amusing glitch is giving all players M4s, no matter what starting weapon you pick in the multiplayer game, and the team is now working on a fix for the issue.
RELATED LINKS: Best Modern Warfare 2 guns, Best loadouts in Modern Warfare 2, Modern Warfare 2 maps