Which is better a pericing gun or needle for a second hole?

As you progress in your piercings from the lobe up the ear I would recommend getting the second and consecutive holes done by needle piercing in the hands of a professional body piercer. See inside the lobe moving up the ear there is a fine feather line of cartilage which gets thicker and denser as you progress up the ear, at some point you will need to start over gauge piercing to ensure the piercings will heal correctly without discomfort from the cartilage inside the tissue.