From Charter Arms Facebook page:
Please be aware we are in the process of redesigning our 9mm PITBULL. Our new design will now be a 5 shot. This decision was made to greatly improve extraction and to bring the 9mm design closer to that of the rest of the PITBULL family of products. This process will take approximately 4-6 weeks with shipments of the New and Improved version starting in July-August.
If you are a current owner of a 9mm PITBULL and would prefer the 5 shot version, please feel free to send your 9mm PITBULL in for a free upgrade starting in August.