A Blackhawk breaking paint can be caused by issues with the feed rate, paint quality, or needed maintenance. Always point the marker in a safe direction and always wear eye protection then check for these issues.
Is your loader feeding fast enough to keep up with your fire rate? Normal gravity loaders only feed about 5 bps and can get jammed up if not agitated enough. If you shoot fast for more than a couple shots the loader won’t keep up. Using an electronic loader will help to feed and keep balls stacked in the feedneck and ready to shoot as fast as you can.
Are you using fresh field grade paintballs? The Blackhawk operates best with paintballs that are not too soft or swollen to break in the gun. Old paintballs can swell up and become too big and fragile if left in poor conditions. During winter months make sure to purchase winter shelled paintballs. When it is cold out normal summer shell paintballs are too fragile and will break in the gun.
Is the ball detent damaged or worn out? Inside the breech is a rubber latch that holds the paintball until the bolt pushes it forward to fire. If this is worn out it will allow paintballs to roll down the barrel and multiple paintballs enter the breech.
Is your barrel too big or too small for the paint you are using? Paint that is too big or small can have friction issues and will break in the barrel.