In order to do this trick you must have a VS with two empty arms as well as two Gatlin guns. Attach both guns to each side of the VS and fire only one of the guns a few times. Then, start firing the second gun. If done correctly, one of the guns will reload while the other is firing and repeat, causing the guns to never stop firing until you run out of bullets or manually reload. This works well against any Akrid Boss, especially the one in Mission 05.