I would like to reload for my Rob Arms XCR-M in .308, but the case mouths are getting severly dented in when the rifle ejects them. Is this common for a semi auto? The gas preasure on the rifle is turned up to maximum as recommended for the break-in period. I did not take any pictures of the damaged brass, but the mouth has a dent in it covering 25% of the mouth. I am assuming these cases are not salvagable. Any advice would be appreciated.