There is plenty of information out there. Just do a duckduckgo search. If you are not after the qualities of the 5R, 4R or Ratchet Rifling specifically, you could discuss it with the barrel seller/maker. Most of those guys are willing to give out information and will give you good stuff rather than taking a chance on receiving information that is inaccurate or incomplete. Not to say that some guys on here don't know there chit, they do, but I like to know what the guy thinks that has been making them and refining the process. $.02