why wouldn't 400 rounds be sufficient for 30 minutes?
i use maybe 400 rounds during a 26 hour scenair game this past spring...and managed to loose track of kills
whats actually important here is to carry enough paint for your playing style. are you heavy on the trigger? shoot at anything that twitches? or are you more careful in picking your shots?
also, if you carry as much paint on you as you can shoot with 1 full air tank to start the day, you will find yourself not running out of one of the other as much.
does your tank shoot 1000 rounds before going empty? start the day with 800 rounds in your hopper and pods. this is a way to tell when you need to refill the tanks as well. plus, you can always borrow a pod of paint on the field. how many times have you been able to borrow a tank?
it would be foolish to carry more paint that you can actually shoot. unless you are in the practice of giving away pods to players. kind of like a water boy
why carry the weight when you can't possibly shoot it if you were to stay on the field long enough? lighten your load, carry what you can shoot.