These balls do not break in the barrel. Over the past few months, my friends and I have gone through about 6 cases of the stuff WITHOUT A SINGLE BREAK. This even included a whole case used in a steady rain at 50 degrees. They are pretty tough, somewhat elastic shells that will take a lot of abuse, but they seem to always break on your intended target. These balls are fairly inexpensive at about $65 a case.
They tend to dimple after they have been around for a few weeks so it's real important to rotate them. I think it's because of their rubbery sheel.
A very good paint for the money and what I will continue playing with unless I find something better. I would give it a ten except it tends to dimple more than other paintballs which does affect accuracy. So I'm giving it a 9.