did a video demonstrating how I slicked up a coach gun for CAS. Hopefully some you will get something out of it if interested. Wish I could have had a reference like this 20 years ago. 
Enjoy!
https://www.youtube.com/watch?v=6p4onxcF3IY
Enjoy!
https://www.youtube.com/watch?v=6p4onxcF3IY