Gas question

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.

The inital 4 setting is just to break the gun in. Once you have a few hundred rounds through it, then you'd reset the system so it reliably ejects with whatever ammo you're using just then.

This is all pretty much SOP with gas-operated guns. Some are more (or less--much less for a few) easily adjustable than others, but you still set it to a spot that will reliably eject.