Open Combat Missions in the Modern Warfare 3 campaign bring the opportunity to change your loadouts on the ground, but you need to unlock weapons first. I will explain how you can get more weapon options and how they work in this guide.
How to Unlock Campaign Weapons in MW3
To unlock weapons for your loadouts in the Modern Warfare 3 campaign, you need to loot new guns and equipment around the map. This only works in Open Combat Missions where loadout changes are possible. Standard missions will have weapons around the map, but they won’t count toward any unlock and you won’t find them in crates.
When you manage to find new weapons around the map in Open Combat Missions, they will only apply to that mission alone. As you get to other OCMs down the line, there is a new list of guns to unlock. So, any progress you make won’t matter after completion. It’s confusing at first because the loadouts display the locked weapons like a progression system.
Any time you search the loadout crates, you can see all of the locked weapons tied to the level in the Modern Warfare 3 campaign. Because there is no way to customize weapons or earn genuine progress, these are essentially placeholders for blueprints around the map. If you find an epic M4 with four attachments, then that is the weapon you will find on the unlock screen.
To see all the unlocked weapons in a given mission, simply press the pause button and look at the bottom left of the menu. There is a small number that shows progress on all the weapons or equipment that have been collected. Some levels only have 10 and others have nearly 30 that you can find.
For a better idea of how the whole system works, check out my guide on whether you can customize weapons in loadouts or not in the Modern Warfare 3 campaign.