I just recieved 2000 hulls from someone who posted a sale on here last week and they came in 2 boxes that were 15.5"x13" and 12" deep. So that is 2418 cubic inches or 1.40 cubic feet per 1000. They fit very snug and couldn't bouce around. I didn't actually count them to verify the 1000/box but I have no reason to doubt it as the guy was great to deal with. The cost per box was $20.16 standard postal service shipping from NY to Ark.
Hope this helps, Dennis