Click on the button that says 'ship' right above your force menu, and it will change to 'armament status'. Then, when you select the gun on the weapons' list, it will bring down the next menu for shell types. Then, when you select the shell type, it will bring down yet another mini-list, asking how many binds' of shells to load.Take as many as you can afford in weight/credits/space, then click 'set'.