Update: Re-used the old sled and threaded it in much further. Still taking paint and shooting with no ill effects. The Black Magic midblock sled is too thin. Using it would put a ton of stress on the delrin bolt pin and wouldn't be a great long term solution.
Short shooting video: http://youtu.be/ql8qfVZOPRs
reballs are .682 and the barrel I used was the kaner .689 so trying to chrono downhill was fun. This is my sale video so didn't want to put a different barrel and misrepresent in any way.