I would just go by what Robarm has said here
http://www.robarm.com/XCR_Technical_Updates.htm
8 to 15 feet for ejected brass after breakin. Your rifle may do that on setting 4 but more than likely will do it on setting 3. I am not sure if it will cause more wear or tear but you would be getting more recoil for no more reliability.
Each rifle is different, hence the adjustable gas. Set it wherever you need to so that the brass ends up between those 2 numbers. If it is between those 2 I would think you are getting the best reliability and recoil.
http://www.robarm.com/XCR_Technical_Updates.htm
8 to 15 feet for ejected brass after breakin. Your rifle may do that on setting 4 but more than likely will do it on setting 3. I am not sure if it will cause more wear or tear but you would be getting more recoil for no more reliability.
Each rifle is different, hence the adjustable gas. Set it wherever you need to so that the brass ends up between those 2 numbers. If it is between those 2 I would think you are getting the best reliability and recoil.