The Assault Rifle is -blam!- medium to long range. Use it only on small maps. The best thing you can do is try to set up the situation to go in your favor. Say you see someone and they get the first couple shots off. If there's cover you can get to, if there's a corner you can run to, use it. You won't win that fight anyway. Other than that, use communication in team based games and get power weapons early on. Halo and Call of Duty multiplayer work the same way. If you want to win, you need to set up the game in your favor and punch the other team in their mouth once it is. Hahaha