Have you tried clearing your cache by following the steps listed here Activision Support as well as re-logging into your game account and re-linking your game account to your Call of Duty account?
Which platform are you playing Ghosts on? Have you checkered under sniper or assault weapons? Also, please try the following steps to make sure everything downloaded properly,
Please try the following troubleshooting tips below for PlayStation and Xbox:
- If you purchased the DLC in-game, you must exit the game to complete your download. Once the download is complete, you will be able to play with the DLC.
- Try downloading the DLC again for Xbox 360, Xbox One, PlayStation 3, or PlayStation 4.
- Clear the system cache on the console.
- Be sure that your PlayStation Network or Xbox LIVE account allows you to download content.
Please try the following troubleshooting tips below for PC:
- Exit Steam.
- Navigate to your Steam directory (C:\Program Files\Steam\) or (C:\Program Files (x86)\Steam\) and delete the AppCache folder.
- Restart Steam and launch your game.