They do allow BB's from previous visits. You have to buy fresh ones on the spot. It's the only way they can confirm that everyone uses the same untampered ammo. Their site mentions they may allow outside BB's in the future, but not at this time.
You must repurchase bb's each time you visit. Asked the same thing last time I went and got told that. It's to play it safe and make 100% sure there aren't any other types of bb in play
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