Since the Black Dragun doesn't have an adjustable reg, and you'd have to buy one in order to up the input pressure, you'd be miles ahead just to buy a color coded spring kit. They sell 'em for like 8 bucks at just about every paintball shop in the world, and they are color coded to make it easier to know what spring to put in (ie, purple spring will give you 280fps, green will give you 300, red will give you 250 etc.)