So I've never figured out how to use an actual infuser. The infusions work good when created on a crafted item (at random) but I buy an infuser but can't ever find a way to apply it to an item. I have an infuser that says it will work with ranged weapons. I have my rifle from the start of the game but cannot figure how to apply it to the weapon. I can pick it up but that's it. And no options when clicking on the rifle itself.