Why does your paintball gun chop paint?

chopping paint is when the paintball is pinched between the bolt and feedneck which "chops" the paintball in half, this commonly happens when cheap paint or brittle paint is used or it occurs when bolt is moving faster than the hopper can feed the paint.

*edit* a CHOP is when the ball breaks in the marker itself normally in the breach. a BREAK is when the ball breaks either in the barrel or the air. THEY ARE 2 COMPLETELY DIFFERENT THINGS