How do you Upgrade Weapons?

To be successful in Missions it is important that you upgrade your weapons whenever possible. Focus on upgrading the main weapon on the AC-130 first, then if you have spare parts go for the secondary weapon and finally your soldiers weapons. You will be able to upgrade weapons when you reach level 10, this will involve fusing them so you increase their power and star rating. Note: You do not need a max level weapon to fuse it. Upgrades range from increasing a gun's rate of fire or reload speed, to improving the effectiveness of the in-game rader. Upgrades can be purchased using the in-game coins or with real money.