I have had trouble-free service from my CA Pitbull other than my needing to replace a defective hammer block. CA sent me the new hammer block and informed me that breakage of this part was very rare.
The "flag" portion broke off and the gun will not fire without this part in place.
Due to the strong spring that needs to be compressed while inserting a pin, replacing the transfer bar is not a fun project. My secret to replacing this part is to use three hands.