Call of Duty: Modern Warfare had a great start with record sales and generally positive reviews. However, some players have noticed that the weapon balance is not exactly where it should be. Specifically, players report that the M4 rifle and 725 shotgun are currently too powerful and negatively impacting the gameplay experience.
Joe Cecot, co-director of Modern Warfare, wrote on Twitter to confirm this. "Changes to the weapon optimization will be made in a future update, he did not say which weapons are specifically addressed, but given the amount of feedback on the M4 and 725, it is likely that these weapons are somehow tampered or altered." [1
It is not yet known when the weapons tuning update will be released. But keep checking GameSpot for the latest information.  Modern Warfare was launched on October 25 and only took three days to reach sales of more than 600 million dollars to earn $ 1 million. Sales in the first three days were better than any other Call of Duty released during this generation of consoles.
Looking to the future, Infinity Ward plans to support Modern Warfare in the long run, starting with a Battle Pass system that will regularly add new cosmetic rewards. The Battle Pass is not yet available, but Activision says it will be live later in 2019.