A Brick has 10, 50 round boxes inside it. Making for a total of 500 rounds. The 250, 333, and 525, boxes are bulk packs. The cartridges are loose inside the box. I buy the bricks for my own use, I buy bulk packs for the Boys and Grand kids. I will take a box of 50 and put in a medicine bottle, then stick it in the fender bags on the 4-wheeler. When it get about half way down I take another box of 50 and refill it. If I am in a hurry and not taking the 4-wheeler I just grab a box and stick it in my pocket. The bulk packs just seem to disappear, kids.