They are bred small. I have the opportunity to go through about 100 or so WC gravid female ball pythons a year. Some of them are good sized, what would be breeders for us. Some are large, even seen one 6'. Then some are small. I had one who was 700 grams after laying a clutch of 7 eggs. I've seen some that look like they were maybe 500-600 grams before they were bred to a male. Actually I should say mating.