In order for the 12gram exp. chamber to work, you're going to need the vertical air kit which will require you to cut a hole in your gun for the adapter. If you don't want to do that, get the PGP C/A kit (http://www.cooper-t.com/sheridan.html). I've never used a better bolt or seen one in action. In order for it to be effective, you'll have to use small paintballs and open your gun's bore to like .695 or more in order to achieve decent backspin. She'll also need a ball detente to keep the balls in the gun. I have experience with the quickstrip bolt, however. It seemed pretty decent, but your stock bolt should be fine. If you elect to go with Coop, mill a quickstrip slot in the gun because without it, it won't quickstrip. Email me if you have any other questions.