We see them have backpacks or bags but rarely do we see what’s inside. They definitely don’t have clothes since they don’t change into anything. Maybe food,water,ammo but they should have more. Or sometimes there packs are too light like they don’t have anything
Presumably they’re only carrying guns they have ammo for, or guns they want others to think they have ammo for. If you got it, may as well use it, and if others think you got it, they may not be so quick to use their own. Also ammo isn’t that hard to make.