I think I've found a bug with the Cocoon perk found on King's Fall Raid weapons. And no, this bug isn't the kind that benefits you in any way.
For example: I have the raid sniper. So when I stow it for a short time, if it's not already reloaded, it will reload itself! However, I've found if I am completely out of ammo, then switch to another weapon and pick up special ammo, it never reloads with my newly picked up ammo no matter how long I wait.
Maybe it's intended to work this way but it doesn't seem like it.